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Climate Change News Summary
Posted on Wednesday, May 14, 2008 @ 1:20 pm by Dave Schumaker
I’m going to summarize two global warming and climate change studies that were published today.
Ice cores reveal fluctuations in the Earth’s greenhouse gases
A core drilled through 3 kilometers of ice in the middle of Antarctica has returned CO2 (carbon dioxide), CH4 (methane) and O2 (oxygen) stretching back 800,000 years. Temperature curves (implied based on the ratio of O2 isotopes) mostly show a close correlation between the amount of CO2 in the atmosphere and the relative temperature.
“The temperature curve over the past 800,000 years matches the CO2 curve beautifully – during glacial periods in which the climate is cold, there is less CO2 in the atmosphere,” says Professor Thomas Blunier from the Centre for Ice and Climate at the Niels Bohr Institute, University of Copenhagen. He explains that when it is cold there is less plant growth, and so there are fewer plants to absorb the CO2 from the air, while more CO2 is absorbed in the oceans, so the final calculation is a low CO2 content in the atmosphere during glacial periods. This produces a lower greenhouse effect, and leads to an even colder climate.
However, the new results show that during the glacial period that occurred between 650,000 and 750,000 years ago, the CO2 level was extremely low – lower than any previous measurements have indicated. It happened twice in this period, while the temperature was not lower than during other glacial periods.
Warming climate is changing life on global scale
A NASA study suggests that human induced climate change is impacting ecosystems and habitats at a large scale. The study looked at physical and biological impacts going back to 1970 and compared them to rising temperatures over that time frame.
Observed impacts included changes to physical systems, such as glaciers shrinking, permafrost melting, and lakes and rivers warming. Biological systems also were impacted in a variety of ways, such as leaves unfolding and flowers blooming earlier in the spring, birds arriving earlier during migration periods, and plant and animal species moving toward Earth’s poles and higher in elevation. In aquatic environments such as oceans, lakes, and rivers, plankton and fish are shifting from cold-adapted to warm-adapted communities.
The team conducted a “joint attribution” study. They showed that at the global scale, about 90 percent of observed changes in diverse physical and biological systems are consistent with warming. Other driving forces, such as land use change from forest to agriculture, were ruled out as having significant influence on the observed impacts.
Conscious use of our natural resources
Posted on Thursday, May 1, 2008 @ 7:40 am by Peter Polito
Arguably Earth’s most dire resource, but only recently receiving any major discussion, is water. As a previous post pointed out the American Southwest is projected to become a drier climate while funding for monitoring and mitigation continues to decrease.
Over the past few years the plight of the Southeast has received a fair bit of press, but overshadowed by Atlanta’s water woes is the brilliance of Clayton County. In the 1980’s the Clayton County Water Authority built a series of wetlands to replace the last step of the water reclamation process. Water entering the sewers continue on to the reclamation facility and pass through the standard filtration systems designed to remove large debris, sediment and any other solids. The purification process is completed by feeding the water into their wetland systems where organisms, from single-celled bacteria to water lilies, do the rest. After the water is gravity-fed through a series of four wetland pools, the water enters their reservoir and is available for reuse. According to a recent story on NPR, of the 26 million gallons used a day in Clayton County, the wetland reclamation process returns 10 million gallons of potable water for future use. Not only are they getting 40% of their water back but the wetlands have created 4,000 acres of green space.
Source: Clayton County Water Authority.
Constructed wetlands are proving to be more efficient, more cost effective, and more environmentally sensitive than comparable secondary treatment methods. The wetlands allow the CCWA to increase its wastewater treatment capacity, while dropping the costs incurred in the process. The cost to build wastewater facilities using constructed wetlands is $4.73 a gallon, compared to nearly $10 a gallon using the more conventional methods.
The Authority’s LAS fields and constructed wetlands are included among the over 4,000 acres of protected green space that will never fall prey to residential or commercial development. This acreage provides for hearty forests and wildlife, not to mention incredible recreational opportunities located in such a close proximity to a major metropolitan city.
In addition to money saved, there have been no complaints about odor and unlike neighboring Atlanta, the residents of Clayton County were never in danger of running out of water during the recent drought.
Study Suggests Emissions Irrelevant to Climate Change
Posted on Wednesday, April 30, 2008 @ 7:59 am by Dave Schumaker
A new study released by the A.M. Obukhov Institute of Atmospheric Physics RAS, in Moscow, Russia claims that human generated emissions of greenhouse gases (such as CO2) are irrelevant to climate change.
The press release is rather light on details, however a PDF of the report can be found here.
The link between the carbon cycle, and human effects caused by emissions, energy use and agriculture, may only be relevant for the next ’several centuries,’ suggest Igor Mokhov and Alexey Eliseev from the A.M. Obukhov Institute of Atmospheric Physics RAS, in Moscow, Russia. The authors used a climate model known as IAP RAS CM to study how feedback between our climate and the carbon cycle changes over time. In their simulations, the authors assumed that fossil fuel emissions would grow exponentially with a characteristic timescale from 50 to 250years.
In their models, Mokhov and Eliseev found that although climate–carbon cycle feedback grows initially, it then peaks and eventually decreases to a point where the feedback ceases. If we succeed in slowing down the rate of emissions, the peak would be reached much later. However, a steep increase in emissions would bring the peak in coupling between climate and carbon emissions even closer.
The authors suggest that we are heading inexorably towards the saturation peak, irrespective of how quickly we get there: “Even weak but continuing emissions lead to eventual saturation of the climate–carbon cycle feedback,” Mokhov and Eliseev explain.
This one study goes counter to about 20 years worth of peer-reviewed research on the topic, so take it with a grain of salt. Of course, this is all that’s needed for opponents of alternative energies to rally behind.
[Via Eurekalert]
The Future of Climate Change Science and Water Resources
Posted on Friday, April 25, 2008 @ 8:30 am by Dave Schumaker
Although the IPCC is not responsible for producing new science, it certainly has a major role in pushing the direction of research. Therefore, any changes to the reporting process of the IPCC are of significance to the geoscience community, especially those who seek funding for research on global change. A recent report in Science highlights an intended reorganization of the IPCC annual report preparation process.
• The first change would ditch the practice of prescribing the scenarios of economic and technological progress driving future greenhouse gas emissions that researchers should incorporate into their modeling, the first step in the process. Delegates also backed the idea of having the communities that correspond to the panel’s three working groups on the science of climate change, its impacts, and mitigation strategies develop their studies in parallel rather than sequentially. Scientists say these changes will reduce the level of uncertainty in their findings, deliver more regional details, and provide policymakers with better clues on how to curb climate change–without lengthening the time from start to finish. The new regime “will expedite and improve the process,” says Richard Moss of the World Wildlife Fund, who helped coordinate the effort for IPCC.
[Via Science]
An editorial by two high-ranking IPCC officials published in a previous issue of Science presents a dissenting view of the intended changes. They contend, “Any move toward more rapid products risks incomplete identification of the range of justifiable views and a consequent reduction of the rigor, clarity, and robustness of the consensus [of climate scientists].”
These intended changes come at a time when the issue of climate change and water resources is (or should be) receiving additional media attention. On April 9, 2008, the IPCC released the Technical Paper on Climate Change and Water that describes the scientific evidence for and potential consequences of global warming. The report also explains methods of adaptation and mitigation that portend a sketchy future for freshwater supply, especially in arid regions of Africa and Asia. The Executive Summary emphasizes,
• “Globally, the negative impacts of future climate change on freshwater systems are expected to outweigh the benefits (high confidence). By the 2050s, the area of land subject to increasing water stress due to climate change is projected to be more than double that with decreasing water stress.”
• “Several gaps in knowledge exist in terms of observations and research needs related to climate change and water.”
[Via IPCC]
The findings of this report suggest that an increase in the knowledgebase for water resources in the United States is of utmost importance. However, the US Geological Survey’s FY 2009 budget for water resources was cut by nearly 17% compared to FY 2008. Some have argued that the Water 2025 initiative and congressional restoration of some budget cuts will offset this major blow to water resource assessment. The US Deparment of Interior’s Water 2025 initiative focuses on improving water resources in the western US, but recent water challenges faced by the southeastern US imply a significant deficiency in the scope of such an initiative.
This article was written by Bob Sas, a Master’s student at San Francisco State University, and kindly submitted to Geology News.
The Future is Drying Up
Posted on Tuesday, April 22, 2008 @ 1:42 pm by Dave Schumaker
During a discussion at lunch on climate change, the Colorado River and the impact on water resources in the Southwest, one of my colleagues reminded me of this article published in the NY Times Magazine in October of 2007. It’s a fascinating (and rather grim) look on the future of water resources in the United States.
Climatologists seem to agree that global warming means the earth will, on average, get wetter. According to Richard Seager, a scientist at Columbia University’s Lamont Doherty Earth Observatory who published a study on the Southwest last spring, more rain and snow will fall in those regions closer to the poles and more precipitation is likely to fall during sporadic, intense storms rather than from smaller, more frequent storms. But many subtropical regions closer to the equator will dry out. The models analyzed by Seager, which focus on regional climate rather than Colorado River flows, show that the Southwest will ultimately be subject to significant atmospheric and weather alterations. More alarming, perhaps, is that the models do not only concern the coming decades; they also address the present. “You know, it’s like, O.K., there’s trouble in the future, but how near in the future does it set in?” he told me. “In this case, it appears that it’s happening right now.” When I asked if the drought in his models would be permanent, he pondered the question for a moment, then replied: “You can’t call it a drought anymore, because it’s going over to a drier climate. No one says the Sahara is in drought.”
I figure this article is apropos, especially because of the recent news of the future of the Colorado River that we posted about last week.
[Via NY Times Magazine]