Carbon-rich soil found to be a major source of warming
In a massive new study published in the influential journal Nature, no less than 50 authors from around the world document a so-called climate system “feedback” that, they say, could make global warming considerably worse over the coming decades. That feedback involves the planet’s soils, which are a massive repository of carbon due to the plants and roots that have grown and died in them. As warming increases, the microorganisms living in these soils respond by upping their rate of respiration, a process that releases carbon dioxide or methane, leading greenhouse gases.



Carbon-fueled vegetation growth spurt won't slow the warming
More plants have been growing due to higher CO2 levels in the air and warming temperatures that cut the CO2 emitted by plants via respiration. The effects led the proportion of annual carbon emissions remaining in the air to fall from about 50% to 40% in the last decade. However, this greening is only offsetting a small amount of the billions of tonnes of CO2 emitted from fossil fuel burning and other human activities and will not halt dangerous global warming. “Unfortunately, this increase is nowhere near enough to stop climate change,” said the study's lead scientist.



Arctic soils contain 10 times atmophreric CO2
Scientists estimate there is more than 10 times the amount of carbon in the Arctic soil than has been put into the atmosphere by burning fossil fuels since the start of the Industrial Revolution. To look at it another way, scientists estimate there is two and a half times more carbon locked away in the Arctic deep freezer than there is in the atmosphere today. Now, with a warming climate, that deep freezer is beginning to thaw and that long-frozen carbon is beginning to be released into the environment.




NASA warms of a growing groundwater crisis
With drought afflicting several parts of the world, and with aggressive use of groundwater in many agricultural regions, this precious water resource is under serious strain, warns NASA hydrologist James Famiglietti. In many parts of the world, in particular in the dry, mid-latitudes, far more water is used than is available on an annual, renewable basis. 



Warming seen increasing carbon emissions from soils
The huge stores of carbon locked in the world's soils are more vulnerable to rising temperatures than previously thought.Researchers found that microbes in the soil were more likely to enhance the release of CO2 in a warming world. Soils from colder regions and those with greater amounts of carbon were seen to emit more as temperatures went up. The world's soils hold about twice the amount of carbon as the atmosphere.




Rising CO2 threatens widespread malnutrition
Rising carbon dioxide emissions are set to make the world's staple food crops less nutritious, according to new scientific research, worsening the serious ill health already suffered by billions of malnourished people.  The surprise consequence of fossil fuel burning is linked directly to the rise in CO2 levels which, unlike some of the predicted impacts of climate change, are undisputed. The field trials of wheat, rice, maize and soybeans showed that higher CO2 levels significantly reduced the levels of the essential nutrients iron and zinc, as well as cutting protein levels.




Canada prepares to enter global corn market
Corn had been long ungrowable in the fertile farmland of Canada’s breadbasket. That is changing as a warming climate, along with the development of faster-maturing seed varieties, turns the table on food cultivation. The Corn Belt is being pushed north of what was imaginable a generation ago. Growing seasons on the Canadian prairie have lengthened about two weeks in the past half-century.




Warming projected to cut food production 2 percent per decade
Climate change will pose sharp risks to the world’s food supply in coming decades, potentially undermining crop production and driving up prices at a time when the demand for food is expected to soar, scientists have found. The scientists concluded that rising temperatures will have some beneficial effects on crops in some places, but that globally they will make it harder for crops to thrive — perhaps reducing production over all by as much as 2 percent each decade for the rest of this century, compared with what it would be without climate change.  And, the scientists say, they are already seeing the harmful effects in some regions.




British wheat production cut 30 percent by extreme weather
The wettest autumn since records began, followed by the coldest spring in 50 years,  has devastated British wheat, forcing food manufacturers to import nearly 2.5m tonnes of the crop. Analysts expect a harvest of 11m-12m tonnes, one of the smallest in a generation, after many farmers grubbed up their failing, waterlogged crops and replanted fields with barley. According to a National Farmers Union poll of 76 cereal growers covering 16,000 hectares, nearly 30% less wheat than usual is being grown in Britain this year.



Warming will make the world hungrier and more chaotic
Drought, rocketing bread prices, food and water shortages have all blighted parts of the Middle East. Analysts say a combination of food shortages and other environmental factors exacerbated the already tense politics of the region. As the Observer reports today, an as-yet unpublished US government study indicates that the world needs to prepare for much more of the same, as food prices spiral and longstanding agricultural practices are disrupted by climate change.




UN fears permafrost thaw could lead to runaway warming
Warming permafrost could release the equivalent of between 43 and 135 billion tonnes of carbon dioxide, the main greenhouse gas, by 2100 -- nearly 40 percent of annual emissions from human sources, a UN report said.  Permafrost now contains 1,700 billion tonnes of carbon, or twice the amount now in the atmosphere, it said.the release of more greenhouse gases would trap more heat in the air and in turn accelerate the melting which could bring an irreversible, runaway effect.



Earth's carbon sink may be 23 percent smaller than estimated
As carbon dioxide levels in the atmosphere continue to climb, most climate models project that the world’s oceans and trees will keep soaking up more than half of the extra CO2. But researchers report this week that the capacity for land plants to absorb more CO2 will be much lower than previously thought, owing to limitations in soil nutrients1.




Prolonged Drought, Searing Heat Threatens US Corn Crop

Experts say parts of five corn-growing states, including Indiana, Kentucky and Ohio, are experiencing severe or extreme drought conditions. And in at least nine states, conditions in one-fifth to one-half of cornfields have been deemed poor or very poor, federal authorities reported this week, a notable shift from the high expectations of just a month ago. Crop insurance agents and agricultural economists are watching closely, a few comparing the situation with the devastating drought of 1988, when corn yields shriveled significantly, while some farmers have begun alluding, unhappily, to the Dust Bowl of the 1930s. 




Enhanced CO2 Forces Plant Growth Spurt, Then Long Decline

Global warming may initially make the grass greener, but not for long, according to new research results. The findings, published this week in the journal Nature Climate Change, show that plants may thrive in the early stages of a warming environment but then begin to deteriorate quickly. Ecologists subjected four grassland ecosystems to simulated climate change during a decade-long study. Plants grew more the first year in the global warming treatment, but this effect progressively diminished over the next nine years and finally disappeared.




Permafrost Emissions Will Accelerate Warming Beyond Previous Projections

Massive amounts of greenhouse gases trapped below thawing permafrost will likely seep into the air over the next several decades, accelerating and amplifying global warming, scientists warn.  Those heat-trapping gases under the frozen Arctic ground may be a bigger factor in global warming than the cutting down of forests, and a scenario that climate scientists hadn't quite accounted for, according to a group of permafrost experts. The scientists predict that over the next three decades a total of about 45 billion metric tons of carbon from methane and carbon dioxide will seep into the atmosphere when permafrost thaws during summers. That's about the same amount of heat-trapping gas the world spews during five years of burning coal, gas and other fossil fuels.




Warming threatens main Chinese crops

China will face yield losses in rice, wheat and corn -- the country's three main crops -- unless it takes steps to offset the effects of climate change, an expert warns.  "The impact of climate change, especially extreme weather and plant diseases and insects, will cause a bigger grain production fluctuation in China and bring more serious threats to the country's food supplies," said the  deputy dean of the Chinese Academy of Agricultural Sciences.




Rising Temperatures Seen to Shrivel Crop Yields

Scientists now wonder if an unusual rise in day-time and, especially, night-time summer temperatures being seen in crop belts around the world. Interviews with crop researchers at American universities paint the same picture: high temperatures have already shrunken output of many crops and vegetables.




UN Food Agency Warns of "Potentially Catastrophic" Food Impacts

“Potentially catastrophic” impacts on food production from slow-onset climate changes are expected to increasingly hit the developing world in the future, and action is required now to prepare for those impacts, the Food and Agriculture Organisation (FAO) warned in a report to the United Nations Framework Convention on Climate Change.




Scientists Foresee Extreme Drought Impacts by 2030
Increasingly dry conditions across much of the globe — including the U.S. — are likely over the next 30 years, a new study predicts. Moreover, by the year 2100 drought in some regions could be unprecedented in modern times.  Increasing drought has long been forecast as a consequence of warming temperatures, but the study from the National Center for Atmospheric Research projects serious impacts as soon as the 2030s. Impacts by century's end could go beyond anything in the historical record, the study suggests.




Large Areas of Soils Found Drying Up
The soils in large areas of the Southern Hemisphere, including large parts of Australia, Africa and South America, have been drying up in the past decade, a new study finds.  Most climate models have suggested that evapotranspiration -- the movement of water from land to the atmosphere -- would increase with global warming, because of increased evaporation of water from the ocean and more precipitation overall. The new research, published online this week in the journal Nature, found that's exactly what was happening from 1982 to the late 1990s.




Warming Is Driving Crops Northward
Warmer and wetter weather in large swaths of the country have helped farmers grow corn, soybeans and other crops in some regions that only a few decades ago were too dry or cold, experts who are studying the change said. The change is due in part to a 7 percent increase in average U.S. rainfall in the past 50 years. The storm tracks are moving northward as the climate warms.




Desert Spreading "Like Cancer" in the Middle East -- Report

The desert is making a comeback in the Middle East, with fertile lands turning into barren wastes that could further destabilise the region, experts said at a water conference.  "Desertification spreads like cancer, it can't be noticed immediately," said Wadid Erian, a soil expert with the Arab League, at a conference on Thursday in the Egyptian coastal town of Alexandria. Its effect can be seen in Syria, where drought has displaced hundreds of thousands of people, ruining farmers and swelling cities, Erian said.





Nile Delta Becoming Poisoned by Salt Water Intrusion
The Nile Delta, Egypt’s bread basket since antiquity, is being turned into a salty wasteland by rising seawaters, forcing some farmers off their lands and others to import sand in a desperate bid to turn back the tide. Over the last century, the Mediterranean Sea, which fronts the coast of the Nile Delta, has risen by six inches and saltwater intrusion has created a major challenge, experts say.
 
 
 



Nitrogen Deficit Could Cut Capacity of Terrestrial Sinks

Humanity's carbon-belching habit is a feast for plants, which consume the greenhouse gas carbon dioxide (CO2) as they grow. But Earth's hungry greenery is going to start running low on nitrogen.  That could leave billions of tons of excess carbon in the atmosphere that would warm the climate an additional 1.19 degrees Centigrade (2.14 degrees Fahrenheit) above current estimates by the year 2100.




Peat: The Hidden Carbon "Time Bonb"

Carbon that forests absorbed over thousands of years is stored in peat and suspended in waterlogged bogs or permafrost. When it is disturbed or drained - as is happening in some areas - the peat can start to decompose and dry out, unleashing greenhouse gases. In North America alone, the peat and the trees growing in it hold as much carbon as would be emitted worldwide by 26 years of burning fossil fuels at current rates.




Climate-driven Crop Shortages Fuel African Wars: Study

Climate has been a major driver of armed conflict in Africa, research shows - and future warming is likely to increase the number of deaths from war.




US Crop Yields Vulnerable to Moderate Warming

Global warming would be bad news for the corn and soybeans that are plentiful throughout the Midwest. Even moderate increases in temperature will decrease yields of corn, wheat, sorghum, bean, rice, cotton and peanut crops.




Even Slow Warming Could Halve Crop Yields

Even if global temperatures rise slowly, climate change could slash the yields of some of the world's most important crops almost in half, according to a new study co-authored by an N.C. State University scientist.




Warming Will Expand Deserts by One-Third: Study

As the world warms over the next century, global deserts could expand by as much as 34 percent, according to a new study, swallowing an area roughly the size of the United States.




Warming Speeds CO2 Release in Northern Peatlands

Regions of Arctic tundra around the world are heating up very rapidly, releasing more greenhouse gases than predicted and boosting the process of global warming. The study indicated a 1* C rise in warmth could release some 40 gigatonnes per years of CO2.




Warming Turns Food Crops Toxic
Staples such as cassava on which millions of people depend become more toxic and produce much smaller yields in a world with higher carbon dioxide levels and more drought.


African Crops Found Especially Vulnerable to Warming
Rapid rises in temperatures worldwide may overwhelm farmers' efforts to keep up, say experts who want funds to breed new crops and freeze heat-resistant strains bred over past centuries.


Warming-Driven Food Shortages Could Bring Down Civilization
Our continuing failure to deal with the environmental declines that are undermining the world food economy -- falling water tables, eroding soils and rising temperatures -- forces the conclusion that a collapse from food scarcity is possible.


Chu Sounds Dire Warning for Agriculture
California's farms and vineyards could vanish by the end of the century, and its major cities could be in jeopardy, if Americans do not act to slow the advance of global warming, Secretary of Energy Steven Chu said.


Major Crop Failures On the Horizon -- Study

By the end of the century, the hottest temperatures in recent history will become typical, and the world's food supply will be in deep trouble as a result.  Rapidly warming climate is likely to seriously alter crop yields in the tropics and subtropics by the end of this century and, without adaptation, leave half of the world's population facing serious food shortages.




Researchers Find Acidification of Kansas Groundwater

Groundwater seems to be taking on carbon dioxide 100 times faster than the atmosphere, according to a new study. A team of researchers have discovered that dissolved carbon dioxide levels in the groundwater flowing beneath the pristine Konza Prairie in Kansas rose 20 percent from 1991 to 2005.

 




Higher Temperatures Turn Plants From Sinks to Sources

Plants are unlikely to soak up more carbon dioxide from the air as the planet warms, research suggests. US scientists found that grassland took up less CO2 than usual for two years following temperatures that are now unusually hot, but may become common. The conclusion parallels a real-world finding from Europe's 2003 heatwave, when the continent's plant life became a net producer, not absorber, of CO2.




Scientists Increase Estimates of CO2 Beneath the Permafrost
The permafrost is starting to melt, and that pent-up carbon is already leaking into the air in the form of carbon dioxide and methane, powerful greenhouse gases. Even worse, there may be more of the stuff than anyone ever thought.


Grazing Animals WIll Reduce Carbon-Absorbing Shrubs
Grazing animals will play a key role in reducing the anticipated expansion of shrub growth in the region, thus limiting their predicted and beneficial carbon-absorbing effect.


UN Chief to G-8: Warming Intensifies Food Crisis
The global food crisis will only worsen because of climate change, the U.N. climate chief said, urging leaders of the world's richest countries  to set goals to reduce carbon emissions within the next dozen years. Food security and soaring oil prices are likely to overtake climate change in the priorities of the G-8 meeting starting Monday, though global warming was the theme set by the host, Japanese Prime Minister Yasuo Fukuda.



Texas Cotton Crop Devastated by Heat, Sandstorms
Blowing sand and blistering heat have badly damaged the cotton crop in Texas, the country's biggest grower, industry analysts said. While most of the country's attention was riveted by the devastating floods which drowned large swathes of the U.S. Midwest cropland, farms in Texas were savaged by heat, wind and blowing sand which scythed through emerging cotton plants.


Biofuel Chase can Spread "Invasive Species"

Fast-growing foreign crops used as biofuels can disrupt new habitats by ousting local plants and animals, an international report said.




Thawing Permafrost May Be Driving GHG Increase
Despite international levels to curb their growth, global emissions of two key greenhouse gases -- carbon dioxide and methane -- rose sharply last year and fears are that melting permafrost might be partly responsible for the latter, federal scientists reported Wednesday.


Mongolian Herders Highlight Growth of Environmental Refugees

Thousands of Inner Mongolians have been forcibly moved off their traditional pastures in the past few years as China fights desertification, the ecological disaster that has triggered massive dust storms across northern China. The Mongolian herders, like millions of other impoverished people around the planet, have become environmental refugees.




Vulnerable Food Reserves Could Trigger Conflicts

Soaring prices for basic foods are beginning to lead to political instability, with governments being forced to step in to artificially control the cost of bread, maize, rice and dairy products. The FAO is expected to say that global food reserves are at their lowest in 25 years and that prices will remain high for years.




CO2 Impacts on Plants Increase Flood Risks
Researchers say efforts to calculate flooding risk from climate change do not take into account the effect carbon dioxide (CO2) has on vegetation. Higher atmospheric levels of this greenhouse gas reduce the ability of plants to suck water out of the ground and "breathe" out the excess.


Desertification Poses Major Threat to Political Stability

Desertification could drive tens of millions of people from their homes, mainly in sub-Saharan Africa and central Asia, a U.N. study warned. People displaced by desertification put new strains on natural resources and on other nearby societies and threaten international instability.




Is the Western US on the Verge of a Megadrought?

Much of the western U.S. may be headed into a prolonged dry spella "perfect drought" that could persist for generations.  The West already has been dry for six years and is looking to be dry again in 2007. But that's nothing compared to what has happened in the region in the past In a study published today in the journal Geophysical Research Letters, researchers Colorado found the Southwest suffered a six-decade megadrought from 1118 to 1179.




IPCC: Plants to Flourish Then Wilt
Global warming is expected to turn the planet a bit greener by spurring plant growth but crops and forests may wilt beyond mid-century if temperatures keep rising, according to a draft UN report.


Warming Cut Crop Yields by $5 Billion in 20 Years
Global warming has cut about $5 billion worth of the world's most commonly grown grains over 20 years. Warming temperatures from 1981 to 2002 cut the combined production of wheat, corn, barley and other crops by 40 million tonnes per year.


Agricultural Yields Seen As First Victims of Warming

The place where most of the world's people could first begin to feel the consequences of global warming may come as a surprise: in the stomach, via the supper plate. A group of agricultural experts are increasingly worried that global warming will trigger food shortages long before it causes better known but more distant threats, such as rising sea levels.




Crops May Be Early Casualty of Warming

Urgent action is needed to make sure a warming climate doesn't slash crop yields, heighten the risk of famine and deepen poverty for the world's most vulnerable.




Tropical Peat Bogs "Overlooked" as Major Source of GHGs

Tropical peat bogs is a vast uncharted source of greenhouse gases that may be doing more to stoke global warming than fossil fuels. Researchers said  that "annual peatland emissions from South-East Asia far exceed fossil fuel contributions from major polluting countries." He estimated emissions from Indonesian peatlands alone total 2 billion tonnes of carbon dioxide a year -- almost a tenth of world greenhouse gas emissions from human activities led by burning coal, oil and natural gas.




CO2 in Siberian Permafrost is Double Earlier Estimates

Ancient roots and bones locked in long-frozen soil in Siberia are starting to thaw, and have the potential to unleash billions of tonnes of carbon and accelerate global warming.




World Grain Production Falls Short Yet Again

This years world grain harvest is projected to fall short of consumption by 61 million tons, marking the sixth time in the last seven years that production has failed to satisfy demand.         
If the weather this year is unusually good, then grain  price rises may be less than those projected, but if this years harvest is sharply reduced by heat or drought, they could far exceed the projected rises.




Soil Bacteria Seen Accelerating Warming

The level of carbon dioxide in the Earth's atmosphere is likely to grow more than expected as soil bacteria, in response to rising temperatures, break down more organic material and produce more CO2, according to results by an international research team.




New Model Intensifies Alarm over Permafrost Thawing

Warming temperatures could melt the top 11 feet of permafrost in Alaska by the end of the century -- damaging roads and buildings with sinkholes, transforming forest and tundra into swamps, and releasing vast amounts of greenhouse gases into the air. A new study released applied one of the most sophisticated supercomputer climate models ever developed to the future of permafrost. The results were startling.

 




Permafrost Runoff Could Alter Ocean Currents

Global warming could melt almost all of the top layer of Arctic permafrost by the end of the century. Scientists say the thaw would release vast stocks of carbon into the atmosphere, threaten ocean currents and wreck roads and buildings across Canada, Alaska and Russia.




"Selective" Logging is Decimating Amazon Rainforest

Damage to the Amazon rain forest may be twice as large than previously thought due to undetected "selective" logging, US and Brazilian forest experts reported on Thursday.




More Snow-Free Tundra Days Accelerate Warming

Melting snow has triggered the warmest summers across Arctic Alaska in at least 400 years, setting in motion tree and shrub growth that will accelerate warming by two to seven times as the century unfolds.




Heatwave of 2003 Cut Crop Yields, Fueled More Warming

Europe's devastating heat wave, which claimed 35,000 lives in 2003, also reduced plant growth across the continent by 30 percent and may have contributed to global warming.




Soil Release of Carbon Intensifies Warming

Global warming is causing soil to release huge amounts of carbon, making efforts to fight global warming tougher than previously thought.




Is Siberian Thaw Beginning of Climate "Tipping Point"?

A vast expanse of western Sibera is undergoing an unprecedented thaw that could dramatically increase the rate of global warming -- and could produce a scenario climate scientists have feared since first identifying "tipping points.




Drought Decimates Illinois Corn Crop

Illinois is going through its worst dry spell in nearly 20 years. And because the state accounted for nearly one-fifth of the nation's corn crop last year, the market is watching closely.




Droughts Trigger Food Shortages in One-Sixth of Nations

One in six countries in the world face food shortages this year because of severe droughts that could become semi-permanent under climate change, UN scientists warned yesterday.




Minnesota Soil Temperature Rise Reflects Warming

Since 1962, Baker and his colleagues have been recording soil temperatures as deep as 42 feet below an open field on the north edge of the university's St. Paul campus. The measurements show sub-surface soil temperatures have increased more than 3 degrees Fahrenheit, a much faster rise than would be expected in a more stable climate.




Crops Found Much More Vulnerable to Warming

Worldwide production of essential crops such as wheat, rice, maize and soya beans is likely to be hit much harder by global warming than previously predicted, an international conference in London has heard. The benefits of higher levels of the main greenhouse gas, carbon dioxide, will in fact be outweighed by the downsides of climate change.




Australia Braces for Severe Climate Impacts

Australians are in for a rough ride from global warming and will have to cope with a warmer, drier world swinging wildly between extremes of drought and flood, bushfires and dust storms.




US West Could Face a Future of "Mega-Drought"

Researchers examining ancient tree ring records have linked prolonged periods of epic drought in the West with warmer temperatures, suggesting that global warming could promote long-term drought in the interior West.  The study maps a 400-year period of recurring mega-droughts that make the West's current five-year dry spell look puny.




Tundra Carbon Release Found to be Accelerating

Dramatic results made public today from a unique 20-year American experiment are raising the spectre of runaway warming above the Arctic tundra that would accelerate global climate change. The findings, if confirmed with additional studies, could also doom Canada's Kyoto plan targets for reducing emissions of carbon dioxide, the leading greenhouse gas. This double whammy arises because U.S. researchers discovered climate warming might trigger conditions where tundra decomposition will dump carbon dioxide into the atmosphere faster than it's soaked up by accelerated plant growth.




Higher Temperatures Drive Crop Yields Down for Four Years

This year's world grain harvest is falling short of consumption by 93 million tons, dropping world grain stocks to the lowest level in 30 years. As rising temperatures and falling water tables hamstring farmers' efforts to expand production, prices of wheat and rice are turning upward.  For the first time, the grain harvest has fallen short of consumption four years in a row.




Study: U.S. Agriculture At Risk From Changing Climate

The closest look yet at climate change in the United States predicts trouble for many U.S. farmers. While  corn production in the Northern Plains should increase,  productivity would drop through the Midwest's Corn Belt and Southeast -- where researchers project a  one-third loss to the agricultural economy if farmers don't prepare for climate change -- and a one-fifth loss even if they do change crops to reflect warmer conditions.




Winter Fungi Growth Could Speed Carbon Release

Tiny fungi that live under the Rocky Mountain snowpack get busy reproducing in the winter and may affect global warming, U.S. scientists said yesterday.  Unlike most life, which hibernates or hunkers down in the winter, these fungi proliferate - creating measurable amounts of nitrogen and carbon dioxide, the researchers said. This could affect global warming - caused to a large degree by both natural and human-made carbon dioxide.

 




Enhanced CO2 Will Cut Plant Diversity

One in every five species of wild flower could die out over the next century if levels of carbon dioxide in the atmosphere double in line with predictions, scientists said. A study of the impact of global warming on plants has found that most of the environmental changes are likely to result in a substantial loss of plant life. Even though plants need carbon dioxide to survive, the research found that higher levels of the gas reduced numbers of wild flowers by 20 per cent, and cut overall plant diversity by 8 per cent.




Plants Seen Flourishing in Short-Term from Warming

Climate change during the past two decades has improved conditions for much of the world's plant life. Global changes in temperature, rainfall and cloud cover have given plants more heat, water and sunlight in areas where climatic conditions once limited growth, according to the study jointly funded by the U.S. National Aeronautics and Space Administration (NASA) and the U.S. Department of Energy.




Land Use Role in Warming Seen Larger Than Previously Thought

The most important anthropogenic influences on climate are the emission of greenhouse gases  and changes in land use. Researchers now  project that half of the observed decrease in diurnal temperature range is due to urban and other land-use changes.  They also estimate that warming due to land-use changes is at least twice as high as previous estimates.




Research: One Degree of Warming Cuts Soy,Corn Yields 17%

Since the 1940s, harvests across the United States have become ever more bountiful as farmers have planted better varieties of crops, generously fertilized them, and gained the upper hand against pests and weeds. But over the past 2 decades, they have had a little help: A new study shows that a surprisingly high percentage of the improvement in yield was due not to farm management but to climate change.The finding suggests that food production in the United States may be more vulnerable to shifts in climate than was previously suspected, a fact that could affect global food security.




African Crop Failures Tied to Warming

Southern Africa is in the midst of a famine; the World Food Program estimates that nearly one-third of Lesotho's 2.1 million residents will need emergency handouts this year. Many scientists say that nearly 40 million other Africans, at risk of starvation, may be among the first human victims of global climate change.




Elevated CO2 Reduces Plant Growth in a Greenhouse World

Researchers at Stanford University concluded that elevated atmospheric CO2 actually reduces plant growth when combined with other likely consequences of climate change -- namely, higher temperatures, increased precipitation or increased nitrogen deposits in the soil.




Western U.S. Water Future Seen as a "Train Wreck"

Global warming will have a devastating effect on the availability of water in the western United States, according to a new study done by a team of scientists. Even a best-case scenario forecasts a virtual train wreck, with supplies falling far short of the projected future demands for water by cities, farms and wildlife, scientists said.




CO2 Diminishes Nutritional Value of Crops

Rising atmospheric carbon dioxide levels may increase agricultural productivity, but reduce the nutritional quality of some crops, a new study suggests. Carbon dioxide (CO2), a greenhouse gas linked to global warming, could help crop plants grow and reproduce more in the temperate zones that now produce most of the world's food. But the price of that bonus could be a reduction in the nutritional value of crops.




Land Use Patterns Seen as Major Climate Driver
The way humans alter the surface of the Earth may be a key factor in climate change, scientists believe. They say changes like urban sprawl, the destruction and planting of forests, and farming and irrigation all have a strong effect on regional surface temperatures, precipitation and larger-scale atmospheric circulation.




Study: Trees' Sink Capacity Overestimated
Scientists have overestimated the potential of trees and shrubs to soak up carbon dioxide from the atmosphere, according to a new study. The reassessment casts doubt on whether planting trees is always a positive step in the fight against global warming, as President Bush and others have suggested.




Grasslands Absorption of CO2 May Be Near End

According to a new study, the world may soon see the end of the "free ride," in which carbon absorption by natural ecosystems ameliorates the rise in atmospheric CO2 due to fossil fuel burning and loss of forest.The ecosystem study of the reaction of a Texas grassland to a range of carbon dioxide levels has shown that soil nitrogen availability may limit the capacity of ecosystems to absorb expected increases in atmospheric CO2.




Drought, Overgrazing Propels Desertification in China

Driven by overgrazing, overpopulation, drought, and poor land management, deserts are slowly consuming vast areas of the country in a looming ecological disaster. From 1994 to 1999, desertified land grew by 20,280 square miles. Desert blankets more than a quarter of China's territory. Sands threaten herders and farmers in a nation with one-fifth of the world's population but only one-15th of its arable land.




Tropical Food Crops At High Risk From Warming

Harvests of some of the world's key food crops could drop by up to 30 percent in the next 100 years due to global warming. New studies indicate that yields could fall by as much as 10 per cent for every one degree Celsius rise in areas such as the Tropics.




Permafrost Turning Into Carbon Source

Global warming may be set to accelerate as rising temperatures in the Arctic melt the permafrost causing it to release greenhouse gases into the atmosphere.




Droughts Seen Accelerating Climate Change

Droughts caused by global warming could set off a biochemical process in northern soils that would release large amounts of carbon dioxide into the air and possibly speed changes in the climate, researchers are reporting today in the journal Nature. The increase in droughts predicted by some climate models could abruptly activate a dormant enzyme in moist, peaty northern soils, triggering decomposition of their organic matter.This decay would release large amounts of carbon dioxide, a "greenhouse gas" thought to cause global warming. The soils are believed to hold 460 billion tons of carbon, or about 60 percent of the amount in the atmosphere as carbon dioxide.




Spreading European Desert Triggers Refugee Migrations

The Sahara has crossed the Mediterranean, forcing thousands to migrate as a lethal combination of soil degradation and climate change turns parts of southern Europe into desert.Up to a third of Europe's soil could eventually be affected.




Warming Will Cut Rice Yields 20% to 100%

Temperature increases anticipated as part of global warming appear to reduce rice yields, a finding with worrisome implications for the third of the world's population that relies on rice as a food staple. University of Florida (UF) researchers have found that above average temperatures interfere with the life cycle and pollination process in rice plants. Modest temperature increases predicted by some climate change scenarios would reduce rice yields by 20 to 40 percent by 2100, while the most severe predicted temperature increases could force yields to zero.




Much of US Braces for Drought

Much of the country's midsection and a broad swath of its southern tier from Arizona to Florida -- roughly a quarter of the territory of the contiguous 48 states in all -- is already experiencing a moderate to severe drought with the peak months for drought still ahead. If long-range forecasts are accurate, conditions may well get worse -- threatening farmers' chronically sagging fortunes.




Drought Could Imperil US Food Supply

Parts of the central U.S. may experience more frequent drought conditions because of increasing greenhouse gases. The central U.S.will likely experience substantial percentage reductions in soil moisture during the summer season by the middle of the next century. The region will be particularly vulnerable to more frequent drought conditions and associated reduction in crop yield, according to researchers at NOAA.




New Borehole Study Confirms Warming

The 20th century was the hottest for more than 500 years. The earth's temperature has increased by about one degree Centigrade (1.8 degrees Fahrenheit) since the 1500s, according to scientists who recently completed a study of borehole measurements. In the Northern Hemisphere it was even faster: 1.1C (2F) in the last 500 years and 0.6 C (1.1F) in the 20th century alone.




Scientists Predict Drought, Disease from Runaway Greenhouse
Large swathes of the planet will be plunged into misery by climate change in the next 50 years, with many millions ravaged by hunger, water shortages and flooding, according to findings from Britain's Hadley Centre for Climate Change.


Desert Conditions Spreading in Southern Europe
The process of desertification has already been underway for nearly 30 years in parts of Spain, Portugal, Greece and Italy, according to a 1996, report by more than 40 European climate scientists working under the auspices of the European Commission.


US Wheatfields Could Be Deserts in a Decade
The great crop-growing plains in the Midwestern United States are far more susceptible to desertification from temperature change than was previously believed, according to 1996 findings by researchers at the US Geological Survey.


Borehole Measurements Confirm Surface Warming
Temperature measurements from boreholes indicate that the surface temperature around the globe has increased, on average, by about 0.9 degrees F (0.5 degrees C) in the 20th century; that the 20th century is the warmest century since at least the year 1500; and that the rate of temperature change in the 20th century is four times greater than the average rate of change over the previous four centuries.


Tundra Turns from Sink to Source
Recent experiments on Alaska's North Slope show that carbon molecules have started moving out of the tundra and into the atmosphere via a network of lakes, streams and rivers in larger amounts than ever before.


Arctic Warming Revealed In Soil, Ocean Measurements
North of the Canadian forests, a series of boreholes in Alaska revealed soil temperature increases of 2 to 5 degrees C. (3.6 to 9 degrees F.) during this century.


NOAA warns of More "Dust Bowls"
As devastating as the 1930s Dust Bowl was, the Great Plains could see even worse droughts over the next century. Two National Oceanic and Atmospheric Administration researchers have concluded that 20th century droughts -- including the eight-year Dust Bowl -- have been only moderately severe and relatively short compared with "megadroughts" in the 13th and 16th centuries. Two human factors could make the Great Plains even more susceptible to a severe drought in the future --land-use practices and global warming.


Alaskan Permafrost Is Melting
The combination of increased annual temperature and increased snowfall in the past 20 years has tended to rapidly increase the temperature of most of the soil and permafrost in central and southern Alaska, causing a net release of CO2. The seasonally-thawed soil layer above the permanently frozen soil layer is penetrating more deeply in recent years, leaving the remaining permanently frozen soil below very close to the thaw point, much of it only a few tenths of a degree C below freezing. The recent warming is also jeopardizing roads, foundations and other structures build on the permafrost.