Posts Tagged ‘Nature Climate Change’

Great Recession Had Little Impact on CO2 Emissions

Tuesday, December 20th, 2011

Worldwide CO2, emissions have risen by nearly 50 percent in the past several decades, with 2010 now holding the record as the year with the most greenhouse gas emissions on record.  Burning fossil fuels released more than 36 billion metric tons of CO2 in 2010, due primarily to growth in China, India, and the United States.  Deforestation is another core cause.

Going back half a century, nothing seems to have set back emissions for many years and that includes the Great Recession that started in late 2008, according to a new study published in the journal Nature Climate Change. Other studies indicate that mankind has burned approximately 50 percent of available fossil fuels if we don’t want the climate to warm by more than two degrees Celsius.  More to the point, we’ll need zero or negative emissions and emissions to peak sometime this decade to avoid any further warming.

Emissions rose approximately 510 million metric tons of carbon to reach 9.14 billion tons in 2010, the most in records dating to 1959, according to the Global Carbon Project.  That represents a 5.9 percent increase, the largest since 2003, when they jumped six percent.  The 2010 global emissions were 33.5 billion tons when converted to carbon dioxide.

“We’re going exactly in the wrong direction for limiting global warming,” said Corinne Le Quere, co-author of the Global Carbon Project’s report and a director of the Tyndall Centre for Climate Change Research at the University of East Anglia, England.  “Governments need to develop ways to boost the economy using renewable energy,” she said.

“Global CO2 emissions since 2000 are tracking the high end of the projections used by the Intergovernmental Panel on Climate Change, which far exceed two degrees warming by 2100,” Le Quere said.  “Yet governments have pledged to keep warming below two degrees to avoid the most dangerous aspects of climate change, such as widespread water stress and sea level rise, and increases in extreme climatic events.”

There’s growing evidence that 2011 will almost certainly be the 10th warmest on record, and the hottest featuring the La Nina phenomenon that brings cooler waters to the surface of the Pacific Ocean, the World Meteorological Organization (WMO).  “There’s clearly a warming trend.  That’s supported by other indicators such as disappearing Arctic sea ice, melting glaciers and rising sea levels,” Peter Stott, head of climate monitoring at the U.K. Met Office, whose own temperature estimates feed into the WMO data, said.

“The global financial crisis was an opportunity to move the global economy away from a high-emissions trajectory.  Our results provide no indication of this happening,” according to the study’s authors.  The study was issued at a planet-warming gases panelat U.N. climate talks in Durban, South Africa.

Writing on Times’ Ecocentric blog, Bryan Walsh notes that “The study underscores just how little we’ve done to slow the increase in carbon emissions. Since 1990 –the base year for the Kyoto Protocol –carbon emissions from fossil fuels have increased by 49 percent, making a mockery of that global treaty’s ambition to cut emissions by at least five percent.  And it’s getting worse –on average, fossil fuel emissions have risen by 3.1 percent a year between 2000 and 2010, three times the rate of increase seen during the 1990s, even as global warming has become a global concern.

According to a Nature blog, “What’s new in this analysis is that it puts the recovery in context with previous global crises.  It also updates a novel type of carbon dioxide accounting pioneered by lead author Glen Peters, who is at the Center for International Climate and Environmental Research in Oslo.  Usually, and under the Kyoto Protocol, carbon dioxide emissions are identified with the nation that produces them.  Yet rich countries have largely achieved cuts in CO2 emissions since 1990 by importing goods made elsewhere.  Around one-fifth of China’s emissions, for example, come from making goods demanded by consumers in other nations.  If you count the CO2 emissions embodied in final consumer demand, the study shows, Kyoto’s ‘developed’ countries are consuming more carbon dioxide now than they did in 1990 — although they report cuts in domestic production.  Even so, 2009 marked the first time that developing countries consumed more carbon dioxide than developed countries.  The crisis may not have fully passed, and it’s too early to tell whether the green stimulus packages introduced in recent years will have a positive impact, the study says.  For the moment it’s sobering to think that the pain caused by the financial crisis made but a small dent in global CO2 emissions.”

As Weather Warms, Some Animals and Plants Get Smaller

Wednesday, November 2nd, 2011

Whether it’s the polar bear or the petite house sparrow, many of Earth’s species seem to be shrinking in size, a new study reports; its authors believe that is likely a result of global warming.  Other experts disagree, noting that the conclusion goes too far, and that global warming should not be blamed for what could be natural changes.  The research was published in the journal Nature Climate Change. 

The study found that 38 of 85 animal and plant species showed a definite reduction in size over decades, including a type of Scottish sheep that is now five percent smaller than a quarter century ago.  Those studies examined species over different time periods and in diverse numbers.  According to the study, species that are getting smaller include cotton, corn, strawberries, bay scallops, shrimp, crayfish, carp, Atlantic salmon, herring, frogs, toads, iguanas, hooded robins, red-billed gulls, California squirrels, lynx and wood rats.  The study notes that the house sparrow’s weight has dropped by one-seventh between 1950 and 1990.  A bird known as the graceful warbler showed a 26 percent weight loss during the same timeframe.

“There is a trend in a number of organisms across the board from plants to big vertebrates getting smaller,” said study co-author Jennifer Sheridan, a biology researcher at the University of Alabama.  “The theory is as things get warmer they don’t need to grow as large.”  The majority of these animals are cold-blooded, so the warmer the weather the faster their metabolism and the more calories they burn, according to Sheridan.  A biological law, called Bergmann’s rule, says that as the weather gets colder, animals get bigger.  This is the unwritten flip side of it, Sheridan said.

Yoram Yom-Tov, a zoologist at Tel Aviv University whose studies Sheridan used in her research, agreed that many species are shrinking, and noted that global warming isn’t the only reason.  “Changes in body size are a normal phenomenon,” Yom-Tov said.  “When conditions are favorable, they increase in size or reproduce at higher rates, and when conditions are deteriorating, they do the opposite.  I think that most species will adapt to climate change and survive.  No need for alarm.”

Many scientists believe that the study confirms that climate change is shrinking many plant and animal species and is likely to have a negative impact on human nutrition in the future.  Warmer temperatures and increasing variability in rainfall are affecting the size of all species in the ecosystem from microscopic sea organisms to land-based predators.  “Our study suggests that ectotherms (cold-blooded animals like toads, turtles, and snakes that rely on environmental heat sources) are already changing a lot,” said David Bickford from the National University of Singapore and the study’s co-author.  “What was most surprising to me was that it was such a uniform signal across all these different organisms,” Bickford said.

Sheridan and Bickford examined fossil records, which they found to be clear-cut: past eras of rising temperatures saw both marine and land organisms becoming progressively smaller.  During a time of warming 55 million years ago — often viewed as an analogue for current climate change — beetles, bees, spiders, wasps and ants shrank by 50 to 75 percent over a period of several thousand years.  Mammals such as squirrels and wood rats also shrank by about 40 percent.

Because warming is occurring at unprecedented rates, “Many organisms may not respond or adapt quickly enough”, especially those with long generation times, according to Sheridan and Bickford.  “We do not yet know the exact mechanisms involved, or why some organisms are getting smaller while others are unaffected.  Until we understand more, we could be risking negative consequences that we can’t yet quantify.”

Stanford biologist Terry Root, an expert in climate change, said the study’s conclusions “seem kind of far-fetched.”

Writing for the Nature.com news blog,  Susan Young says that “Temperature-linked changes in precipitation also affect the size of organisms.  Higher temperatures lead to drier environments, and Sheridan and Bickford suggest that reductions in size will be most pronounced in areas where global warming causes reduced precipitation as well.  Tropical trees, toads and mammals are known to grow slower during drought years and under experimental drying conditions.  Other environmental changes will also affect life on earth.  As the atmosphere loads up with carbon dioxide, so do the planet’s oceans, which raises the acidity of the water.  Higher acidity reduces the rate at which organisms like corals and oysters can form their shells.  The result, the authors say, is that these ocean creatures shrink.  The growth of red algae and phytoplankton are also hampered by the lower pH.  The authors note that the warming-shrinking trend does not apply to every organism, such as those with longer generation times or some at higher latitudes.  This variation exacerbates the problem.  If all organisms in a given ecosystem shrank on scale with one another, smaller predators could eat smaller prey that eat smaller plants, and all would be fed.  But that is not what ecologists are observing.  Organisms change with variable intensity depending on their lineage, size and location, and ecosystems are likely to be thrown off balance.”