Thursday, July 30, 2015

Agriculture vital to tackling effects of climate change

Sam Otieno in SciDev.net: Agriculture should receive more attention as climate change could affect rainfall rates and patterns, resulting in more droughts and increased catastrophic flooding that could affect food production across the world, according to experts.

At a meeting of the United Nations Framework Convention on Climate Change (UNFCC) panel last month (1-11 June) in Bonn, Germany, the experts discussed the need to make agriculture more prominent in a global treaty on climate change expected to be signed in Paris, France in November-December this year.

Scientists have warned that Sub-Saharan Africa is particularly vulnerable to the threat of El Nino as 95 per cent of its crop production area relies entirely on rainfall. Under climate change, this means that multiple stresses such as drought interact, causing large decreases in productivity.

The UNFCC Subsidiary Body for Scientific and Technological Advice (SBSTA) that marshals scientific evidence to support countries’ decisions to be included in the treaty, says that a central objective of agricultural research, extension, education and rural credit systems must be to help farmers and producers successfully adapt to changing climatic conditions.

....“It is difficult to be prescriptive on adaptation and mitigation strategies because options and needs vary largely in space and time,” said Julian Ramirez-Villegas, a, who researches in climate change impacts and adaptation at CIAT. “Something that is clear is that for most countries in Africa adaptation is a priority, but we need to understand the mitigation impacts of any implemented adaptation actions....

Climbing beans growing in the province of North Kivu, Democratic Republic of Congo, shot by Neil Palmer (CIAT), Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license 

Monday, July 27, 2015

Disaster displacement on the rise

Environmental News Network: In the last seven years, an estimated one person every second has been forced to flee their home by a natural disaster, with 19.3 million people forced to flee their homes in 2014 alone, according to a new report.

The research suggests disaster displacement is on the rise, and as policy leaders worldw
ide advance towards the adoption of a post-2015 global agenda, the time has never been better to address it.

In the report, the Internal Displacement Monitoring Centre (IDMC) of the Norwegian Refugee Council (NRC) released today its global report, The Global Estimates: People displaced by disasters. The report reveals how, in 2014, 17.5 million people were forced to flee their homes by disasters brought on by weather-related hazards such as floods and storms, and 1.7 million by geophysical hazards such as earthquakes.

“The millions of lives devastated by disasters is more often a consequence of bad man-made structures and policies, than the forces of mother nature,” said Jan Egeland, Secretary General of NRC. “A flood is not in itself a disaster, the catastrophic consequences happen when people are neither prepared nor protected when it hits.”...

Stillaguamish River (South Fork) flood at Granite Falls in 2006, 9 feet above flood stage. Shot by Walter Siegmund, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Sunday, July 26, 2015

Global study of seed consumption uncovers wider risk to plant species

Deborah Smith in the University of New South Wales Newsroom: The first worldwide study of animals and the seeds they eat has overturned a long-held assumption – that large animals mainly eat large seeds. The finding by UNSW Australia scientists has implications for conservation showing that a wider variety of plants than is often thought could be at risk if large animals go extinct and do not disperse their seeds.

In a comprehensive study, UNSW’s Si-Chong Chen and Professor Angela Moles compiled and analysed data on more than 13,000 animal-seed interactions, based on previously published reports. “It is the first broad-scale study of the relationship between animal body mass and ingested seed size ever undertaken,” says Ms Chen, a PhD candidate in the UNSW School of Biological, Earth and Environmental Sciences.

“We covered all vertebrate groups – fish, amphibians, reptiles, birds and mammals. And we included animals from many different areas – from the Arctic tundra to the tropical rainforests.”...The smallest seeds in the study were the tiny seeds of the mountain snowberry, and they were eaten by the smallest animals in the study – skinks on the Chatham Islands near New Zealand. The largest seeds were the 9-centimetre long seeds of the African tropical forest tree, Balanites wilsonia. They were eaten by the largest animals in the study – 4-tonne African elephants.

“It has long been predicted that as the body size of animals increases so does the size of the seeds they ingest,” says Ms Chen. “Big animals do eat some big seeds from fleshy fruits. But the prediction is wrong because it overlooks the fact that big animals like buffalos, cows, deer and zebras also accidentally vacuum up hundreds of small seeds as they graze on short grassy vegetation.”...

Sunflower with bee, shot by Rasbak, Wikimedia Commons, under the Creative Commons Attribution- Share Alike 3.0 Unported license 

Mowing dry detention basins makes mosquito problems worse

University of Illinois News Bureau: A study of the West Nile virus risk associated with “dry” water-detention basins in Central Illinois took an unexpected turn when land managers started mowing the basins. The mowing of wetland plants in basins that failed to drain properly led to a boom in populations of Culex pipiens mosquitoes, which can carry and transmit the deadly virus, researchers report.

...The team, led by University of Illinois postdoctoral researcher Andrew Mackay, found that mowing down cattails and phragmites, two invasive plants that tend to permeate stormwater basins, adds a lot of plant debris to the water.

“We suspect bacteria quickly colonize the waterborne debris, and mosquito larvae feed on the bacteria,” said Illinois entomology professor Brian Allan, a co-author on the study with Mackay, Illinois Natural History Survey entomologist Ephantus Muturi and U. of I. natural resources and environmental sciences professor Michael Ward.

“After aquatic plants were mowed in the basins, we saw a large increase in the number of Culex pipiens mosquito larvae in the basins, which had relatively few before mowing,” Mackay said. “And perhaps more importantly, we caught about twice as many adult Culex mosquitoes in traps at basins after these plants were mowed, compared with basins where the aquatic vegetation was left intact.”

Mowing phragmites, a tall and sturdy invasive grass, also dispersed a host of bird species that liked to roost in the grass, Allan said.  “We had observed that these phragmites-invaded basins would become colonized by large communa
l roosts of birds,” he said. “And we thought that was important because birds are the natural reservoir hosts of West Nile Virus.” The researchers suspected that a bird roost near a mosquito nursery might increase the West Nile virus risk to people living nearby.

“Instead, we found that the presence of a communal bird roost actually decreased West Nile virus risk,” Allan said. “That may be because these wetland roosts include a variety of bird species, many of which are not good reservoirs of the virus. They don’t amplify the virus like other bird species more associated with residential areas do – the American robin, for example....

Rather than decreasing risk, mowing wetland plants in dry detention basins can exacerbate a mosquito problem, researchers found. Photo by Andrew Mackay

Green light for malaria vaccine for Africa

Tania Rabesandratana in SciDev.net: The first malaria vaccine has received the green light from European regulators today, opening the door for vaccination campaigns for infants in Africa. This a big leap forward for the RTS,S vaccine after decades of research. Also known under the commercial name Mosquirix, the vaccine is intended to protect children aged six weeks to 17 months against the mosquito-transmitted Plasmodium falciparum parasite that causes malaria.

“RTS,S is an imperfect vaccine, providing only partial protection against clinical malaria,” says Brian Greenwood, a clinical tropical medicine researcher at the London School of Hygiene & Tropical Medicine in the United Kingdom. Nevertheless, today’s approval is an “important landmark” that can help control malaria where other methods, such as using bed nets impregnated with insecticides, are not effective enough, Greenwood adds.

According to the World Health Organization, 562,000 people died from malaria in Africa in 2013, of whom 82 per cent were children under five.

The main evidence that the vaccine is safe and effective comes from a large clinical trial conducted in seven African countries, the European Medicines Agency said in a statement. According to this trial, Mosquirix provides “modest protection”, which decreases after one year, but despite this “limited efficacy”, its benefits outweigh the risks, the agency says....

USAID photo of Angolan children with bednets for malaria protection

Brain-eating parasite discovered in drinking water of Louisiana

Sean Waters in the Standard Daily: Naegleria fowleri, a deadly brain-eating amoeba is currently under investigations in the recent death of a Minnesota teen, following findings that the single-celled organism is now thriving in northern US waters due to help from climate change.

Climate change is causing the summers to get hotter at this period, and this amoeba is known to thrive in warmer waters of southern United States – according to Dr. Bruce Hirsch, an infectious diseases specialist at North Shore University Hospital in Manhasset, NY. “Climate change may be playing a role,” Hirsch said.

And then the US Centers for Disease Control and Prevention (CDC) says the amoeba is “heat-loving.” Despite the fact that the Naegleria fowleri common in several US rivers and lakes, the chances of getting infected with it inside your brain are low, and the CDC said only 35 people were infected between 2005-2014 within the US.

The CDC further revealed that the deadly amoeba causes the amebic meningoencephalitis, an infection that destroys brain tissues. While people cannot get infected with the parasite by drinking contaminated water, it does get into the human body through the nose, from where it finds its way into the brain....

Histopathology of amebic meningoencephalitis due to Naegleria fowleri. Direct fluorescent antibody stain. Via the CDC

Pakistan heat wave subsides as death toll climbs to 860

Business Mirror via AP: The devastating heat wave that struck southern Pakistan last weekend is slowly subsiding but the toll was still climbing on Thursday to a total of 860 confirmed deaths, a senior health official said.

Pakistan’s deadliest heat wave on record comes just weeks after soaring temperatures caused nearly 2,200 deaths in neighboring India, raising fears that South Asia could be seeing some of the devastating effects of human-caused climate change.

The crisis centered in the southern port city of Karachi was worsened by poor local services, including a faulty power grid and shortages of potable water. And the heat wave struck as the city’s Muslim majority was observing the dawn-to-dusk fasting month of Ramadan.

Jam Mehtab Hussain, the provincial health minister in the southern Sindh province, of which Karachi is the capital, said that despite lower temperatures people were still being admitted to hospitals with heat-related ailments—though in smaller numbers than in previous days.

Ahmad Kamal, a spokesman for the National Disaster Management Authority, said authorities were providing free medical treatment to people in Karachi. He said the situation was improving due to lower temperatures....

Saturday, July 25, 2015

Greenland’s undercut glaciers melting faster than thought

A press release from NASA: Greenland's glaciers flowing into the ocean are grounded deeper below sea level than previously measured, allowing intruding ocean water to badly undercut the glacier faces. That process will raise sea levels around the world much faster than currently estimated, according to a team of researchers led by Eric Rignot of the University of California, Irvine (UCI), and NASA's Jet Propulsion Laboratory, Pasadena, California.

The researchers battled rough waters and an onslaught of icebergs for three summers to map the remote channels below Greenland's marine-terminating glaciers for the first time. Their results have been accepted for publication in the journal Geophysical Research Letters and are now available online.

"Measurements are challenging to obtain beneath hundreds of meters of seawater in poorly charted, ice-infested fjords," Rignot wrote. He and co-authors Ian Fenty of JPL, Cilan Cai and Yun Xu of UCI, and Chris Kemp of Terrasond Ltd., Seattle, obtained and analyzed around-the-clock measurements of the depth, salinity and temperature of channel waters and their intersection with the coastal edge of Greenland's ice sheet.

The team found some glaciers perched on giant earthen sills, protecting them from the punishing salt waters for now, while others were being severely eroded out of sight beneath the surface, meaning they could collapse and melt much sooner.  "Numerical ice sheet models do not take into account these interactions and as a result underestimate how fast the glaciers will respond to climate warming," said Rignot....

Glaciologists from the University of California, Irvine, and JPL mapped remote Greenland fjords by ship in 2014. Their findings show that Greenland's glaciers are likely to be melting faster than previously thought. Credits: UCI/Maria Stenzel

Experts push climate-proof cities, coastal communities

Imelda V. Abano at InterAksyon.com: Experts meeting here say climate-proofing a city or coastline is urgently needed to protect millions of people and key infrastructure. From Manila to New York, cities and coastal areas across the globe are increasingly vulnerable to the impacts of climate change coupled with population growth and poverty.

The adaptations prompted by climate change are meant to minimize risks from extreme weather events, powerful storm surges, sea level rise, droughts, rising temperatures and other effects of a changing climate.

Urban populations, according to the United Nations, is projected to increase from 3.9 billion in 2014 to 6.3 billion in 2050. Asia, the most climate-vulnerable region despite its lower level of urbanization, is home to 53 percent of the world's urban population, followed by Europe with 14 percent and Latin America and the Caribbean with 13 percent.

Smart planning of cities and coastal areas, such as building or planning defenses, securing water supplies or moving people to higher ground, is essential to prepare for the climatic forces, said Steven Wade, head of the Scientific Consultancy at the Met Office, a United Kingdom-based national weather service.

Wade, who presented climate model outputs for climate adaptation in cities at the World Engineers Summit (WES) organized by the Institution of Engineers Singapore, said that adaptation of cities is a significant challenge for planners and engineers, particularly in cities with ageing infrastructure, rapid growth and vulnerable coastal locations....

An aerial night view of Marina Bay, Singapore, shot by Nicolas Lannuzel., Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Climate change effects could cost investors $4 trillion in assets, report warns

Maria Galluci in the International Business Times: Private investors risk losing more than $4 trillion in assets due to the devastating effects of climate change. Rising sea levels, intense flooding and more severe storms threaten to wipe out or diminish portfolios due to property damage, weaker growth and lower asset returns, the Economist Intelligence Unit said in a report Friday.

Assets at stake amount to roughly one-fourth of U.S. gross domestic product. The number could swell to nearly $14 trillion if the Earth’s temperatures warm by a staggering 6 degrees Celsius (10.8 degrees Fahrenheit) compared to the pre-industrial era. From the public-sector perspective, extreme warming represents value losses of $43 trillion, or 30 percent of the entire stock of the world’s manageable assets, the report said.

“Institutional investors need to assess their climate-related risks and take steps to mitigate them; very few have begun to do this,” the report said.

Climate scientists say the world is on track to warm by at least 2 degrees Celsius (3.2 degrees Fahrenheit) by 2050 if countries don’t take dramatic steps to reduce greenhouse gas emissions from power plants, tailpipes and buildings. Even lesser degrees of warming will have dire consequences for the world’s food supplies, coastal communities and human health....

2008 flooding from Hurricane Ike in Key West, Florida, National Guard photo

Reducing vulnerability through a better understanding of migration and adaptation in the Ganges delta in Bangladesh

Jon Lawn and Michele Leone in the Dhaka Tribune (Bangladesh): An abundance of scientific evidence shows that the people living in deltas have an increased vulnerability to sea-level rise and effects of climate change. In 2007, the Intergovernmental Panel on Climate Change (IPCC) reported that low-latitude and less developed areas generally face greater risk, for example in dry areas and mega-deltas. These risks increase vulnerability of specific groups such as the poor.

The poor and vulnerable have migrated in different forms to cope with the disruptions climatic changes has brought upon their lives. Research is crucial to understanding the suitability of migration as an adaptation option to the threats of climate change, and the implications migration has on society and the environment. There is a new project tackling these issues in Bangladesh: a research collaboration between the Bangladesh University of Engineering and Technology (BUET) and the University of Southampton in the UK, which is part of a larger initiative studying migration and adaptation across Africa and South Asia.

The “Deltas, vulnerability and Climate Change: Migration and Adaptation” (DECCMA) project is a five-year long program of applied research which started in early 2014, focusing on the potential and limits of adaptation options in deltaic environments.  The project will analyse the impacts of climate change and changes in other environmental  pressures (such as demand for agriculture or damming rivers) across three contrasting deltas: The Ganges-Brahmaputra-Meghna in both Bangladesh and West Bengal, the Mahanadi delta in India, and the Volta delta in Ghana. The University of Southampton provides the overall leadon the project, partnering with BUET, Jadavpur University in Kolkata, India and the University of Ghana, who lead research in the delta study sites.

We aim to understand the effectiveness of adaptation options for individuals and communities in the coastal zone of the Ganges-Brahmaputra delta, whilst also evaluating the potential for migration to be an active and positive response to climate change. Ultimately, the project team anticipates that the uptake of a robust scientific evidence base for decision-makers and practitioners will lead to improved livelihoods and reductions in poverty in delta regions....

An outline map of the Ganges Delta by John Oldale, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Mangroves help protect coastal areas against sea level rise

Blue & Green Tomorrow: Mangrove forests could play a crucial role in protecting coastal areas from sea level rise caused by climate change, according to new research involving the University of Southampton. A joint study between researchers at the University of Southampton along with colleagues from the Universities of Auckland and Waikato in New Zealand used leading-edge mathematical simulations to study how mangrove forests respond to elevated sea levels.

Taking New Zealand mangrove data as the basis of a new modelling system, the team were able to predict what will happen to different types of estuaries and river deltas when sea levels rise. They found areas without mangroves are likely to widen from erosion and more water will encroach inwards, whereas mangrove regions prevent this effect – which is likely due to soil building up around their mesh-like roots and acting to reduce energy from waves and tidal currents.

Coastal estuaries and recesses in coastlines that form bays receive the run-off from erosion on steep catchments, which give them the tendency to fill in over time. As they infill, the movement of the tidal currents over the shallow areas create networks of sandbanks and channels. The sand banks grow upward to keep pace with water-level changes, while the channels get deeper to efficiently drain the excess water out to sea.

The researchers’ latest work shows that mangroves can facilitate this process, by adding leaf and root structures into the accumulating sediment, which increase the elevation while enhancing the trapping of new sediment arriving from the catchment.

Dr Barend van Maanen from the University of Southampton explains: “As a mangrove forest begins to develop, the creation of a network of channels is relatively fast. Tidal currents, sediment transport and mangroves significantly modify the estuarine environment, creating a dense channel network. Within the mangrove forest, these channels become shallower through organic matter from the trees, reduced sediment resuspensions (caused by the mangroves) and sediment trapping (also caused by the mangroves) and the sea bed begins to rise, with bed elevation increasing a few millimetres per year until the area is no longer inundated by the tide.”...

Mangroves in Zanzibar, shot by Fanny Schertzer, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Thursday, July 23, 2015

UNHCR Malawi helps flood victims to rebuild shattered lives

A press release from the UNHCR: The floods, when they came, came without warning. They were Malawi's worst in 20 years, sweeping through 15 districts in January 2015 and forcing 174,000 people to flee their
homes. Sixty-two people were killed and thousands more risked disease. Now, thanks to nearly US $600,000 from a special UN emergency fund, UNHCR Malawi has given affected populations a chance to rebuild their lives.

The UN's Central Emergency Response Fund (CERF) has enabled UNHCR Malawi to provide core relief items to 8,120 households in the worst-hit districts of Machinga, Zomba, Mulanje and Phalombe. Between May 24 and June 4 this year, kitchen sets, blankets, sleeping mats and insecticide-treated mosquito nets were distributed to thankful locals.

Women were particularly excited by the kitchen sets, having had to try and find work to raise money to buy cooking pots, plates, cups, and other household items lost in the floods.

"I was going to sell sand, but now I do not have to," one woman told UNHCR. "It would take me a very long time to recover the lost items, but this has now changed, thanks to UNHCR."

Men, too, were grateful for UNHCR's help. "The blankets and mats are just what we needed to pull through this bad weather," said one male recipient. "And the mosquito nets will safe guard against malaria."

Locator map of Malawi by TUBS, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Wednesday, July 22, 2015

As the oceans warm, wide-ranging species will have an edge

Terra Daily via SPX: Marine species that already have large ranges are extending their territories fastest in response to climate change, according to new research from University of British Columbia biodiversity experts.

The study is one of the first comprehensive looks at how traits--other than thermal niche--impact marine animals' ability to respond to climate change. It could help improve global predictions of how different species redistribute as the oceans warm, and identify species in greatest jeopardy.

"We have a bit of a mystery as to why some animals are moving quickly into cooler waters, like the green sea urchin that is decimating kelp forests in Tasmania, while other species aren't moving at all," says UBC biodiversity researcher Jennifer Sunday, lead author of the study.

"Our findings indicate that animals which already have wide-latitudinal ranges, habitat generalists, and species with high adult mobility displayed the quickest and greatest range shifts. The flip side is that small-ranging species are in increased jeopardy as our planet's oceans continue to warm."....

Oscar (Astronotus ocellatus), a popular aquarium fish from South America, shot by Jón Helgi Jónsson (Amything), Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Thursday, July 16, 2015

Farming is driving force in drying soil in Northern China

Purdue University News: An important agricultural region in China is drying out, and increased farming may be more to blame than rising temperatures and less rain, according to a study spanning 30 years of data. A research team led by Purdue University and China Agricultural University analyzed soil moisture during the growing season in Northern China and found that it has decreased by 6 percent since 1983.

The optimal soil-moisture level for farmland is typically 40 percent to 85 percent of the water holding capacity, and the region's soil is now less than 40 percent and getting drier. If this trend continues, the soil may not be able to support crops by as early as 2090, said study leader Qianlai Zhuang, Purdue's William F. and Patty J. Miller Professor of Earth, Atmospheric and Planetary Sciences and Agronomy.

"The soil moisture declined by 1.5 to 2.5 percent every decade of the study and, while climate change is still a factor, this water depletion appears to be largely driven by human activities," Zhuang said. "A 10 percent decline in soil moisture over the course of a century would have major implications for agriculture and the fresh water supply in this heavily populated area."

Forty percent of the nation's population resides in Northern China, according to the country's population census office. The region also accounts for 65 percent of the nation's cropland, Zhuang said.

"The drying of soil in Northern China has been well documented, but its causes and the impacts of agricultural intensification in general have been understudied," he said. "This information is critical to improvement of agricultural practices and water resource management. The demand for food and water is increasing, but current practices to meet this demand threaten the future security of water resources. Unfortunately, with the growing world population, more and more regions could face the same circumstances of agricultural intensification for food security."...

This is a map of soil moisture trends in Northern China during the growing seasons from 1983-2012. The shading shows the trend in satellite-observed surface soil moisture, and the circles represent monitoring stations within agricultural plots. A Purdue University-led research team found that farming was more of a driver in the drying of the soil than rising temperatures and declining rainfall. The change in volumetric water content is shown. (Purdue University image/Yaling Liu) 

“Doha has just three days’ supply”: are water shortages the biggest threat to the Middle East?

Karim Elgendy in City Metric: Those who visit the Middle East and North Africa from more temperate climates are often struck with how hot and dry the region is, and how scarce its rainfall. Some wonder why cities became established here, and how they continue to exist despite the lack of renewable freshwater.

These concerns are not entirely groundless. Yet these cities’ existence is not in any way miraculous: it’s merely an example of how one can strike an unsustainable balance between growth and limited resources.

The cities in this region may appear unusual today, but like most around the world, most of them grew out of settlements that had access to enough water to sustain life. This is not to say the region’s cities only grew around water sources: have other favourable geographical characteristics, too.

Many of the region’s cities benefited – still benefit – from proximity to a water body that moderates their temperature. Quite a few benefited from a geography that allows natural ports: these include Alexandria, Jeddah, Aden, Haifa, Acre, Byblos, Casablanca,Tunis, Muscat, and Manama. Others – Doha, Dubai, Kuwait – began life as small pearling ports. The region’s cities are where they are because of water, not despite the lack of it.

Some regional cities benefited from proximity to land trade routes (Aleppo, Marrakesh, Sana’a); others grew near large navigable rivers (Cairo, Baghdad, Basrah). In some cases, cities grew in locations where the climate was more temperate due to altitude (Amman, Aleppo, Sana’a, Taif). In at least two cases – Jerusalem and Mecca – it was spiritual significance that drove city growth.

One factor remains constant in the development of all these cities, though: none of them would have been possible without access to fresh water, be that ground water, surface water (rivers), or direct rainfall. The region’s cities are where they are because of water, not despite the lack of it....

An old postcard of the Quweik River in Aleppo,Syria

Lyme disease is spreading, government research finds

WFLA.com: Lyme disease is gradually spreading from the Northeast and becoming more common farther south and west, government researchers reported Wednesday. A county-by-county look at the infections shows it’s found in four times as many counties now as it was in 1993, a team from the Centers for Disease Control and Prevention found.

It’s not clear why – experts say climate change, forest regrowth and the spread of deer might all be factors. What is clear is that many more people than before need to watch out for the ticks that carry the infection, CDC says.

“Over time, the number of counties identified as having high incidence of Lyme disease in the northeastern states increased more than 320 percent: from 43 (1993-1997) to 90 (1998-2002) to 130 (2003-2007) to 182 (2008-2012),” Kiersten Kugeler of the CDC’s center in Forth Collins, Colorado, and colleagues write in their report. The northern coast of New Jersey is no longer a hotbed of new Lyme infections, but now east-central Pennsylvania is, they said....

An adult deer tick

Warming of oceans due to climate change is unstoppable, say US scientists

Suzanne Goldenberg in the Guardian (UK): The warming of the oceans due to climate change is now unstoppable after record temperatures last year, bringing additional sea-level rise, and raising the risks of severe storms, US government climate scientists said on Thursday.

The annual State of the Climate in 2014 report, based on research from 413 scientists from 58 countries, found record warming on the surface and upper levels of the oceans, especially in the North Pacific, in line with earlier findings of 2014 as the hottest year on record.

Global sea-level also reached a record high, with the expansion of those warming waters, keeping pace with the 3.2 ± 0.4 mm per year trend in sea level growth over the past two decades, the report said. Scientists said the consequences of those warmer ocean temperatures would be felt for centuries to come – even if there were immediate efforts to cut the carbon emissions fuelling changes in the oceans.

“I think of it more like a fly wheel or a freight train. It takes a big push to get it going but it is moving now and will contiue to move long after we continue to pushing it,” Greg Johnson, an oceanographer at Noaa’s Pacific Marine Environmental Laboratory, told a conference call with reporters.

“Even if we were to freeze greenhouse gases at current levels, the sea would actually continue to warm for centuries and millennia, and as they continue to warm and expand the sea levels will continue to rise,” Johnson said....

Wednesday, July 15, 2015

Typhoon Nangka continues on course towards Japan: AIR analysis

The Insurance Journal: Catastrophe modeling firm AIR Worldwide has released an analysis of Typhoon Nangka, which is currently a Category 3 storm “with a central pressure of 950 mb and maximum 10-minute sustained wind speeds of 80 knots (~106 mph 1-minute sustained). The storm is located approximately 1,250 km (775 miles) from Iwakuni, Japan, Nangka, and is moving northward at 15 km/h (9 mph).

“Once the intensity of a Category 4 Super Typhoon, Nangka has weakened and maintained its current intensity for the last 72 hours,” said Dr. Anna Trevino, scientist at AIR Worldwide. “It is located in a favorable environment with very little vertical wind shear and warm sea surface temperatures, but nearby dry air is being wrapped into the center, preventing further convective growth and intensification.

 “High pressure to the northeast is steering Nangka toward Japan, and the typhoon is forecast to make landfall as a Category 2 or weak Category 3 storm between the isla
nds of Kyushu and Shikoku Thursday (local time) and rapidly weaken. Because landfall is not for at least 48 hours, there is uncertainty in the intensity of the storm at landfall. This is the first typhoon landfall in Mainland Japan has seen in 2015, with the exception of Typhoon Noul, which quickly weakened before making landfall as an extratropical storm in May.”

According to the Japan Meteorological Agency (JMA), Nangka is expected to slightly strengthen over warm ocean waters during the next two days before landfall, causing rough seas, anticipated to impact shipping....

Typhoon Nangka on July 13, 2015, via NASA

Ocean warming leads to stronger precipitation extremes

A press release from the Helmholtz Centre for Ocean Research-Kiel: Due to climate change, not only atmospheric, but also oceanic, temperatures are rising. A study published in the international journal Nature Geoscience led by scientists at the GEOMAR Helmholtz Centre for Ocean Research Kiel shows that increases in sea surface temperature can contribute to the development of stronger precipitation events. Their findings are underpinned by flash-flooding in June in the Olympic city of Sochi, Russia.

That the temperatures on our planet are rising is clear. In particular, the increasing emissions of greenhouse gases such as carbon dioxide continue to warm the atmosphere. The effects of global warming on the hydrological cycle, however, are still not fully understood. Particularly uncertain is how the strength of extreme summertime thunderstorms have changed, and how it may change in the future. In coastal regions neighboring warm seas, the sea surface temperature can play a crucial role in the intensity of convective storms. The Black Sea and eastern Mediterranean have warmed by about 2 C since the early 1980s. Russian and German scientists investigated what impact this warming may have had on extreme precipitation in the region.

“Our showcase example was a heavy precipitation event from July 2012 that took place in Krymsk (Russia), near the Black Sea coast, resulting in a catastrophic flash food with 172 deaths”, said Edmund Meredith, lead author of the study. “We carried out a number of very-high-resolution simulations with an atmospheric model to investigate the impact of rising sea surface temperatures on the formation of intense convective storms, which are often associated with extreme rainfall”, Meredith continued. Simulations of the event with observed sea surface temperatures showed an increase in precipitation intensity of over 300%, compared to comparable simulations using sea surface temperatures representative of the early 1980s.  “We were able to identify a very distinct change, which demonstrates that convective precipitation responds with a strong, non-linear signal to the temperature forcing”, Prof. Douglas Maraun, co-author of the study added.

At the end of June 2015, the nearby Olympic city of Sochi experienced an unusually intense precipitation event. Over 175 mm of rain was recorded in 12 hours, showing the relevance of the scientists work.  “Due to ocean warming, the lower atmosphere has become more unstable over the Black Sea and eastern Mediterranean. We therefore expect that events like those in Krymsk or Sochi will become more frequent in the future”, added the Kiel-based climate scientist.

Rain near a San Francisco beach, shot by the incomporable Brocken Inaglory, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Mobile schools acclimatise to educate girls in rural Kenya

Kagondu Njagi at the Thomson Reuters Foundation:  At 16 years of age, Nagirasia Lengima is already a mother of two. But parenthood doesn't stop her from indulging in her latest passion: school. Like a growing number of girls from nomadic communities in northern Kenya, Lengima is defying cultural prejudices - and climate pressures - by getting an education at a mobile school.

Run by non-profit groups, the schools bring learning to girls whose families are forced to move around the region to survive. In Laisamis village, Marsabit County, at a school run by the Nairobi-based development charity Adeso, it is Lengima's turn to demonstrate what she has picked up from the morning session.

After playing around with some numbers on the chalkboard, she elicits cheers from the 59 other pupils in the class as she produces the answer with a double stroke. "Mathematics and Kiswahili are my favourite subjects," said Lengima. "I want to go into business in the future."

But circumstances are conspiring against her. Teachers have largely abandoned the area to escape sporadic attacks by Islamist militant group Al Shabaab. And increasingly erratic weather often pushes pastoralist families away from their settlements in search of water and grazing, limiting children's access to formal education.

Temperatures in Northern Kenya can reach over 30 degrees Celsius, and the region regularly suffers from both drought and heavy rainfall. Adeso works with the weather to give girls access to informal schooling which otherwise may have been impossible....

Christopher Michel took this photo of a Masai girl doing math problems in 2013, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Insurance industry 'should be forced to insure those at climate risk'

Brad Allen at edie.net: The insurance industry should be forced to protect citizens at risk from climate change, a new report from the University of Cambridge's Institute for Sustainability Leadership (CISL) has claimed.

The report, titled Insurance regulation for sustainable development, analysed the role of the insurance industry in protecting societies against climate risk. It found that, as well as providing financial protection, insurers could encourage people to better protect themselves from climate risks through incentives in insurance contracts.

The industry also has a unique expertise in identifying and mitigating risk, argued the report, while the global nature of insurance markets would help to spread the financial impact of climate disasters, especially for poor regions. As a result, the report urges policy makers to “utilize insurance regulation as an essential policy instrument to protect populations and assets from climate risks”.

Put simply, lead author of the study Dr Ana Gonzalez Pelaez argues that as many people as possible need to have access to insurance. Gonzalez Palaez will present her findings at the United Nations Third Financing for Development Conference this week in Addis Ababa. Commenting on the launch of her report, Gonzalez Palaez said: “Insurance should receive higher emphasis to ensure delivery on various policy commitments across the Post 2015 agenda....

Cyclone damage in South Townsville, Australia, shot by Rob and Stephanie Levy, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license 

Nearly 9,500 people die each year in London because of air pollution

Adam Vaughn in the Guardian (UK): Nearly 9,500 people die early each year in London due to long-term exposure to air pollution, more than twice as many as previously thought, according to new research. The premature deaths are due to two key pollutants, fine particulates known as PM2.5s and the toxic gas nitrogen dioxide (NO2), according to a study carried out by researchers at King’s College London.

The study – which was commissioned by the Greater London Authority and Transport for London – is believed to be the first by any city in the world to attempt to quantify how many people are being harmed by NO2. The gas is largely created by diesel cars, lorries and buses, and affects lung capacity and growth.

London, Birmingham, and Leeds are among the UK cities that have been in breach of EU safety limits on NO2 for five years, prompting legal action that led to a supreme court ruling in April that the government must publish a clean-up plan by the end of the year.

Previous research attributed 4,267 annual premature deaths to PM2.5s in 2008, based on 2006 levels of the particulates. Subsequent falls in those particulates and a change in methodology that excludes natural sources of the pollutant sees that figure fall to 3,537 for 2010 levels of PM2.5s in the new study. However that fall is more t
han cancelled out by the addition of an estimated 5,879 deaths from NO2 each year, bringing the total early deaths from both pollutants in 2010 to 9,416....

London view from St. Paul's, shot by Ian Buchanan, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license

Sunday, July 12, 2015

Evidence from past suggests climate trends could yield 20-foot sea-level rise

University of Florida News: When past temperatures were similar to or slightly higher than the present global average, sea levels rose at least 20 feet, suggesting a similar outcome could be in store if current climate trends continue. Findings published in the journal Science showed that the seas rose in response to melting ice sheets in Greenland and Antarctica, said lead author Andrea Dutton, a University of Florida geochemist.

“This evidence leads us to conclude that the polar ice sheets are out of equilibrium with the present climate,” she said.

Dutton and an international team of scientists assessed evidence of higher sea levels during several periods to understand how polar ice sheets respond to warming. Combining computer models and observations from the geologic record, they found that during past periods with average temperatures 1 to 3 °C (1.8 to 5.4 °F) warmer than preindustrial levels, sea level peaked at least 20 feet higher than today.

“As the planet warms, the poles warm even faster, raising important questions about how ice sheets in Greenland and Antarctica will respond,” she said. “While this amount of sea-level rise will not happen overnight, it is sobering to realize how sensitive the polar ice sheets are to temperatures that we are on path to reach within decades.”

The researchers concluded that sea levels rose 20 to 30 feet higher than present about 125,000 years ago, when global average temperature was 1 °C higher than preindustrial levels (similar to today’s average). Sea level peaked somewhere between 20 and 40 feet above present during an earlier warm period about 400,000 years ago, when global average temperatures are less certain, but estimated to be about 1 to 2 °C warmer than the preindustrial average....

NOAA image of the Ross Ice Shelf in Antarctica

Tropical peatland carbon losses from oil palm plantations may be underestimated

A press release from the University of Minnesota: Draining tropical peatlands for oil palm plantations may result in nearly twice as much carbon loss as official estimates, according to a new study by researchers from the University of Minnesota Institute on the Environment and the Union of Concerned Scientists in the journal Environmental Research Letters.

Peatlands — waterlogged, organic soils — have developed over thou
sands of years as carbon storage systems. In Southeast Asia, peat swamp forests cover about 250,000 square kilometers, a land area about the size of Michigan. In the past 15 years, peatland forests have been rapidly drained and cleared to make way for oil palm and pulpwood plantations. Draining exposes the upper peat layer to oxygen, raising decomposition rates and soil carbon losses. Most of that carbon is emitted to the atmosphere, speeding up climate change.

Kimberly M. Carlson, a postdoctoral research scholar with IonE’s Global Landscapes Initiative, and UCS researchers Lael K. Goodman and Calen C. May-Tobin designed their research to support site-specific greenhouse gas emissions assessments in tropical plantations. “We wanted to know whether water table depth could be used as a proxy for soil carbon loss in peatland plantations,” Carlson explained.

...The study, a comprehensive analysis of scientific literature on tropical plantation peatland carbon balance, found a correlation between long-term water table depth (the distance from the soil surface to the water surface) and soil carbon loss rate. This finding suggests that peat water table monitoring could help companies more accurately measure their greenhouse gas emissions.

The researchers compared two measurements of carbon loss: subsidence and mass balance. To find the subsidence rate, scientists measure how much the land has sunk over time and how much carbon is stored in the soil. Subsidence models alone cannot inform the global warming potential of peatland drainage.

...Key findings of the study: The lower the water table, the higher the rate of carbon loss[, and m]ore studies in tropical peatland plantations are needed to reduce uncertainty about the global warming potential of peat drainage....

A palm oil plantation in  Cigudeg, Bogor, shot by Achmad Rabin Taim, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license 

Volcanic eruptions slow down climate change - temporarily

Space Daily via SPX: Although global concentration of greenhouse gases in the atmosphere has continuously increased over the past decade, the mean global surface temperature has not followed the same path. A team of international reseachers, KIT scientists among them, have now found an explanation for this slowing down in global warming: the incoming solar radiation in the years 2008-2011 was twice as much reflected by volcanic aerosol particles in the lowest part of the stratosphere than previously thought. ....

For the lowest part of the stratosphere - i. e. the layer between 10 and 16 kilometres - little information was available so far, but now the international IAGOS-CARIBIC climate project combined with satellite observations from the CALIPSO lidar provided new essential information. According to the study, the cooling effect due to volcanic eruptions was clearly underestimated by climate models used for the last Intergovernmental Panel on Climate Change (IPCC) report.

Led by the University of Lund, Sweden, and supported by the NASA Langley Research Center, USA, and the Royal Netherlands Meteorological Institute, three major German atmospheric research institutes were also involved: the Max Planck Institute for Chemistry in Mainz (
MPI-C), the Leibniz Institute for Tropospheric Research in Leipzig (TROPOS) and the Karlsruhe Institute of Technology (KIT). Since more frequent volcanic eruptions and the subsequent cooling effect are only temporary the rise of Earths' temperature will speed up again. The reason is the still continuously increasing greenhouse gas concentration, the scientists say.

..."Overall our results emphasize that even smaller volcanic eruptions are more important for the Earth's climate than expected", summarize CARIBIC coordinators Dr. Carl Brenninkmeijer, MPI-C, and Dr. Andreas Zahn, KIT. The IAGOS-CARIBIC observatory was coordinated and operated by the MPI-C until the end of 2014, since then by the KIT....

Unknown 1830 painting of an eruption in Italy, a Wellcome Image, Wikimedia Commons, under the Creative Commons Attribution 4.0 International license

Coal giant exploited Ebola crisis for corporate gain, say health experts

Suzanne Goldenberg in the Guardian (UK): Public health experts involved in the response to the Ebola crisis have condemned what they described as a ludicrous, insulting and opportunistic attempt to exploit the disease for corporate gain by the world’s largest privately-held coal company.

As part of a PR offensive to rebrand coal as a “21st-century fuel” that can help solve global poverty, it has emerged that at the height of Ebola’s impact in Africa, Peabody Energy promoted its product as an answer to Africa’s devastating public health crisis.

Greg Boyce, the chief executive of Peabody, a US-based multinational with mining interests around the world, included a slide on Ebola and energy in a presentation to a coal industry conference in September last year. The slide suggested that more energy would have spurred the distribution of a hypothetical Ebola vaccine – citing as supporting evidence a University of Pennsylvania infectious disease expert.

The World Health Organisation believes nearly 27,000 people contracted Ebola in an outbreak of the virus in West Africa last year, and more th
an 11,000 died – although the international agency believes that is probably an underestimate.

Public health experts who were involved in fighting the spread of Ebola were outraged at Peabody’s suggestion that expanding energy access with coal generation could have hindered the spread of Ebola and helped with the distribution of a vaccine – especially as there is no approved vaccine against the disease....

Coal stockpile at the Peabody Coal's Kayenta mine, Peabody Coal photo, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license

Saturday, July 11, 2015

Saskatchewan wildfires could burn until fall

CBC News: The fires burning in northern Saskatchewan could burn until the first snowfall, according to researchers. Kerry Anderson, a research scientist with the Canadian Forest Service, said the weather pattern known as El Nino, which is caused by the warming of the Pacific Ocean off the coast of South America, is responsible.

He expects weather conditions will settle down in Saskatchewan in the coming weeks, but warmer than normal temperatures will likely persist in B.C. and Alberta. Anderson said even if crews bring the Saskatchewan fires under control, they may not actually be out until the fall. "The large fires that are burning there will continue to burn until they are contained or until a fire-ending event may occur, and that may just end up being the first snowfall."

Fire rages near Mark Paquette's cabin on Nemeiben Lake. Late on July 8, 2015, Paquette said his cabin had been spared. (Submitted by Mark Paquette) Wildfire expert Mike Flannigan said tinderbox conditions that have lead to the destructive fires in the West can be blamed on climate change.

"Our weather this year has been very hot, dry and windy," said the University of Alberta professor. "This is consistent with what we expect with climate change. I'm not saying every year is going to be a bad fire year, but we are going to see a lot more fire on the landscape."...

An aerial view of a fire in Saskatchewan from 2009, shot by White White, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license 

Parched paddies strike Thai junta's economic weak spot

Jerome Taylor in Seed Daily via AFP: ...Thailand's vital rice belt is being battered by one of the worst droughts in living memory, forcing impoverished farmers deeper into debt and heaping fresh pain on an already weak economy -- seen as the junta's Achilles heel.

When they seized power in May 2014, Thailand's generals promised to restore order and prosperity after months of street protests paralysed the elected government of Yingluck Shinawatra and brought the economy to a near standstill.

By severely curtailing civil liberties, former army chief turned Prime Minister Prayut Chan-O-Cha has largely managed to renew calm. But the generals have proven less adept at kickstarting what was once one of Southeast Asia's most vibrant economies.

Post-coup gains of a rebound in tourism and increased fiscal spending have been offset by disappointing exports, declining manufacturing and weak local demand. In May the country's economic planning agency further revised down its GDP growth forecast for the year to between 3.0-4.0 percent, one of the lowest rates in Asia and well below Prayut's hopes for at least 4.5 percent.

Now the kingdom faces the prospect of a dismal main harvest of rice -- traditionally one of the country's top exports.

Water levels in some of the main reservoirs are at their lowest levels in 20 years prompting the junta to call on farmers in the Chao Praya river basin to delay sowing crops. Prayut also ordered officials to clear irrigation channels, dig more ground wells and employ cloud seeding technology to create artificial rainfall. But the wet season has yet to arrive in earnest and water remains precariously elusive for many....

A rice plantation near Chiang Mai, Thailand, in wetter times, shot by Martin-Manuel Beaulne, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 4.0 International3.0 Unported2.5 Generic2.0 Generic and 1.0 Generic license 

Africa: Indigenous knowledge key to climate change adaptation

Michel Nkurunziza in AllAfrica.com via the New Times: Scientists have called for the integration of indigenous knowledge to combat global warming and enhance adaptation to climate change. According to researchers from East Africa, on-farm experiences by smallholder farmers and pastoralists and indigenous knowledge can contribute effectively to coping with climate change.

The scientists made this proposal while presenting their findings at the UNESCO scientific conference currently taking place in Paris, France, under the theme, "Our Common Future under Climate Change." "We need to harness indigenous knowledge and revive traditional natural resource governance of landscapes.

There is less appreciation of pastoralists' ideas, for example. Being connected to environmental resources the pastoralists' society is sensitive to climate change and, therefore, responds to th
e change as they deal with pasture and water," Benoit Hazard, an anthropologist from Institut National des Sciences Humaines et Sociales in Kenya, who is currently conducting research on resilience in East Africa said.

"We have traditional societies with specific knowledge to link things with ecological conditions, who know where water sources are and how to adapt. They need to be supported to mix their knowledge with agriculture practices. In Kenya, some have become agronomists."...

Animal husbandry in the Congo, USAID photo by L. Rose

Why climate talks need to focus on agriculture

Frank Rijsberman in SciDev.net: Negotiators at the Paris climate talks in December (COP 21) will focus on reaching a truly universal and legally binding agreement to drive the world’s transition towards resilient, low-carbon societies and economies. This is being talked about as humanity’s last chance to avoid truly disastrous effects for our planet — the floods in the Philippines and persistent drought  in Thailand are just two current examples of the types of events that climate change makes more likely.

In parallel, the scientific community’s focus will be on using and creating practical solutions to complex climate challenges. This week, scientists are gathering in France for a conference hosted by UNESCO (the UN Educational, Scientific and Cultural Organization) to debate evidence-based solutions.

Agricultural scientists are getting organised to increase their involvement in such climate meetings, which the energy and transport sectors often dominate.

Food systems’ high sensitivity to climate is well-known — maize production, for example, could fall by a whopping 40 per cent by the end of this century. Less widely recognised is that agriculture is also a major driver of climate change. Agrifood systems — systems involved in producing, processing and transporting food — are estimated to contribute at least a quarter of global, human-caused greenhouse emissions. It is therefore hard to imagine a successful climate treaty without agrifood systems as a central element.

Agricultural scientists at this week’s meeting will lay the groundwork for a more ‘climate smart’ agriculture, and wider recognition of soil as a carbon reservoir with a major impact on the climate system....

A plowed field in Poland, shot by Krzysztof T, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license

Typhoon lashes China after more than a million people evacuated

Sue-Lin Wong in Reuters: One of the most powerful typhoons to strike eastern China in decades disrupted air, rail and sea transport on Saturday after forcing the evacuation of more than a million people from the provinces of Zhejiang and Jiangsu, state media reported.

Typhoon Chan-Hom was packing winds of 162 kph (101 mph) as it hit the city of Zhoushan, slowing from an earlier speed of 173 kph (108 mph). It could be the most powerful typhoon to hit Zhejiang in July since the Communist Party took power in 1949, the National Meteorological Center said.

In Shanghai, the commercial capital, Pudong International Airport canceled 500 flights while Hongqiao Airport canceled 250 because of the typhoon, the official People's Daily newspaper said.

The typhoon brought heavy rain to Shanghai as well as the provinces of Anhui and Fujian, besides Jiangsu and Zhejiang, the weather service said....

Chan-Hom on July 10, 2015, via Himawari-8 AHI images provided by the Japan Meteorological Agency and composited by Meow, a work of  University of Wisconsin–Madison SSEC/CIMSS, Wikimedia Commons

Wednesday, July 8, 2015

Groundwater from aquifers important factor in food security

A press release from the University of Illinois News Bureau: Thirsty cities, fields and livestock drink deeply from aquifers, natural sources of groundwater. But a study of three of the most-tapped aquifers in the United States shows that overdrawing from these resources could lead to difficult choices affecting not only domestic food security but also international markets.

University of Illinois professors of civil and environmental engineering Ximing Cai and Megan Konar, along with graduate student Landon Marston and Lehigh University professor Tara Troy, studied groundwater consumption from three main aquifer systems. Reliance on these aquifers intensified so much from 2000 to 2008 that it accounted for 93 percent of groundwater depletion in the U.S. They published their findings in the Proceedings of the National Academy of Sciences.

The U.S. Geological Survey identifies the Central Valley aquifer in California, the High Plains aquifer in the Great Plains states, and the Mississippi Embayment aquifer in the lower Midwest as being managed unsustainably, which means that water is being extracted from the aquifer faster than it is replenishing. ... The researchers tracked water consumption from the aquifers to see where the water was going, both in terms of geography and usage. For example, when water was used to irrigate a crop, the researchers tracked where those crops were shipped.

“When we think of water, we think of direct water, the water that comes out of our faucets. But we actually use a lot of embodied water in our everyday lives – the water footprint to produce a product,” Konar said. “We looked at the water implicitly being transferred between states and countries in the products.”

The researchers found that the vast majority – 91 percent – of embodied groundwater from these three aquifers stayed within the U.S. The remaining 9 percent was exported internationally. They identified the states most heavily reliant on each aquifer, and the breakdown of what was produced using water from each aquifer. For example, the largest percentage of water from the High Plains aquifer irrigated grains, while the largest contribution from the Central Valley aquifer in California went to producing meat...

A groundwater irrigation pump in the UK, shot by John Poyser, Wikimedia Commons via Geograph UK, under the Creative Commons Attribution-Share Alike 2.0 Generic license

Catastrophic Chinese floods triggered by air pollution

Roland Pease at Science News: What atmospheric scientist Jiwen Fan saw on her television in July 2013 appalled her. The worst flooding to hit China in 50 years was happening in Sichuan province, in the same place that had been devastated by a massive earthquake just 5 years earlier. Over the course of 5 days, 73 centimeters of rain pounded the mountains, peaking at 29 centimeters in a single day. Rivers burst their banks and poured through city streets, washing away homes, factories, and bridges. Steep valley slopes collapsed in deadly landslides. About 200 people died, and a further 300,000 were displaced.

But Fan was worried about more than just the immediate effect of the floods. The Richland, Washington–based researcher—an expert on air pollution and climate at the Pacific Northwest National Laboratory in Richland, Washington—wondered how they had gotten so strong so fast. The Sichuan basin, surrounded by mountains that trap smoke billowing from its industrial centers, is “notorious” for its dirty air, she says. Did air pollution play a role? To find out, she and her team of Chinese, American, and Israeli researchers designed precision computer simulations to model what had happened.

Air pollution can affect precipitation in many ways. Sometimes, the aerosol particles in smoke can reduce or delay rain. Sometimes, they can make thunderstorms more intense. Their best understood interaction is in changing how water vapor condenses to form droplets in clouds. But Fan and her team have proposed a first: that pollution also changes some air circulation patterns that lead to rainclouds.

In the case of the Sichuan storms, they write in a paper published online before print in Geophysical Research Letters, soot in particular contributed to the catastrophic flooding. It prevented rainclouds from forming over the basin during the day, leading to more intense rainfall in the mountains that evening. “We were amazed at the scale of the effect the pollution had,” Fan says. “Effectively it redistributed the precipitation from the wide area of the basin into the mountains.”...

From the 2013 flooding in Sichuan, shot by 人神之间, Wikimedia Commons, under the  Creative Commons CC0 1.0 Universal Public Domain Dedication