Saturday, February 26, 2011



Google News has a very interesting Jan. 22 article by Richard Ingham titled, Climate change: Dogs of law are off the leash, in which he points out that climate change litigation is a rapidly developing area of law with hundreds of billions of dollars at stake. He writes,Compensation for losses inflicted by man-made global warming would be jaw-dropping, a payout that would make tobacco and asbestos damages look like pocket money. Imagine: a country or an individual could get redress for a drought that destroyed farmland, for floods and storms that created an army of refugees, for rising seas that wiped a small island state off the map.” At:

On February 1 E2 Wire ran an article by Andrew Restucci titled, Scientists ask Congress to put aside politics, take 'fresh look' at climate data. It gives the text – well worth reading - of a Jan. 28 letter signed by 18 scientists (8 of whom are members of the U.S. National Academy of Sciences) from various universities and research centers. Among other things, the letter says, “Some view climate change as a futuristic abstraction. Others are unsure about the science, or uncertain about the policy responses. We want to assure you that the science is strong and that there is nothing abstract about the risks facing our Nation.” At:

On February 1, announced that Vestas, the Danish wind turbine manufacturer, won the Zayed Future Energy Prize, worth $1.5 million. “The renewable energy award, the largest of its kind, was given to Vestas during the recent World Future Energy Summit in Abu Dhabi. The company was chosen for its “relentless innovation over the past thirty years to make wind power a commercially viable power source”.” At:

On June 10, 2010, Senator Tom Carper spoke on the floor of the U.S. Senate against Senator Murkowski’s legislation to prevent the EPA fro regulating carbon emissions under the Clean Air Act. Her legislation (Senate Joint Resolution 26) was defeated by a vote of 47 for and 53 against. You can watch his 8-minute video clip, Senator Carper Votes in Favor of Climate Science, at:

The February 13 NY Times Week in Review had an article by Elisabeth Rosenthal titled, Huff and Puff and Blow Your House Down. It pointed out that dikes, buildings and bridges are often built to withstand a “hundred-year storm,” meaning that there is a 1% chance that a storm that strong will happen in any given year. “But what happens when 100-year storms are seen every 10 years, and 10-year storms become common? How many structures will reach their limits?” Insurance companies are having to deal with increasing risks of loss from extreme weather as the world warms. This is of particular concern for structures along coasts, which face the dual risk of increasing storm intensity and rising sea levels. At:

Reuters for Feb. 17 had an article by Deborah Zabarenko titled, Rising seas threaten 180 US cities by 2100 – study. In it she reported that a sea level rise of only 1 meter would threaten 180 American Cities, with the most severely affected - Miami, New Orleans, Tampa, FL, and Virginia Beach, VA - losing more than 10% of their land area. While the IPCC projected that the global average temperature might rise 2ºC (4.4ºF) by 2100, Jeremy Weiss, the author of the study, thinks it might be 4.4ºC (8ºF). A lot depends on how seriously and soon the U.S., China and other major emitters reduce their GHG emissions. At:

If emissions continue to increase at 3% per year, emissions would increase by a factor of 16 by 2100, and the rise in temperature would be a whole lot more than 8ºF.

Theo Romeo has an article in the Feb. 22 CleanEnergy Authority with the title, New solar carports charge electric vehicles on the cheap. Recognizing that 35-40% of a city’s downtown area is for parking lots, the companies American Clean Energy and Envision Solar have announced a new product and leasing structure where they install solar panels over parking lots to provide both electric vehicle charging stations and shade. The parking-lot owner leases the system for a low monthly fee with no upfront costs. It sounds like a winner, as more cars become all electric or plug-in hybrids. At:

Presumably the car owner pays for the electrical energy used, which costs much less than the equivalent amount of gasoline, since electric motors are so much more energy efficient than gasoline engines.

The following items are from the Environmental and Energy Study Institute (EESI), Carol Werner, Executive Director. Past issues of its newsletter are posted on its website under "publications"

EESI’s newsletter is intended for all interested parties, particularly the policymaker community.

UK Think Tank Introduces Fuel Rationing Concept to Cut Greenhouse Gas Emissions

On January 18, the Lean Economy Connection, a London-based think tank, published a report commissioned by the All Party Parliamentary Group on Peak Oil, a multi-party panel of lawmakers, suggesting that fuel rationing might be necessary by 2020 to meet the United Kingdom’s (UK) carbon emissions target and to prepare for fossil fuel scarcity. The report calls for an electronic carbon trading system, which would distribute free Tradable Energy Quotas (TEQs) to all adult citizens, who would then buy and use electricity and fuel, paying for it as usual, but also giving up a certain number of TEQs depending on the carbon content of the fuel they buy. The scheme could involve two credit card numbers, said John Hemming, chair of the panel, with one linked to the customer’s bank account and another linked to their TEQs account. Once their TEQ supply has been depleted, customers could buy surplus TEQs from others who have some left over. Shaun Chamberlain, a co-author of the report, stated, “the only way of keeping energy prices as low as possible in a time of constrained supply is to reduce demand, and that’s what TEQs do.” The TEQs would provide incentives to live a low-carbon lifestyle, which would strengthen the market for green technology and renewable energy. Caroline Lucas, leader of the U.K. Green Party and vice chair of the panel, said that using TEQs is “the most equitable way and the most certain way that we have to make sure we can meet our emission reduction targets.”

For additional information see: Time, Bloomberg, Report

Report Questions Role of Shale Gas as Bridge to Low Carbon Future

On January 19, a new report from the UK-based Tyndall Centre for Climate Change Research warned that without a global carbon price, the expanding shale gas industry will worsen climate change and siphon money away from renewable energy projects. The report is the first attempt to measure the global warming impacts of the shale gas boom. Shale gas is natural gas extracted from underground shale formations using a method called hydrofracturing, or fracking. The practice of fracking has come under scrutiny recently due to concerns about the use of chemicals and their impact on water resources. Researchers estimated that if the world taps less than half of the natural gas found in shale, it would release an additional 3 to 11 parts per million (ppm) of carbon dioxide (CO2) into the atmosphere, and the report acknowledges that shale gas releases fewer greenhouse gas (GHG) emissions than oil or coal. However, Kevin Anderson, lead researcher at the Tyndall Centre, said, “in the absence of any strong carbon dioxide cap at a global level, all that will happen is that shale gas will be burned in addition to coal — not as a substitute.” The Tyndall Centre has called for a moratorium on fracking until the U.S. Environmental Protection Agency (EPA) has finished its investigation on fracking’s potential health risks, and warned against labeling shale gas as a bridge to a global low-carbon future.

For additional information see: Reuters, Report

ExxonMobil Expects Carbon Emissions to Rise 25 Percent in 20 Years

On January 19, in a preview of ExxonMobil’s annual Outlook for Energy report, the company predicted that global carbon emissions will rise by almost 25 percent in the next 20 years. The report also stated that the need for energy efficiency and low-carbon technology will be at its peak after 2030. The report was previewed at the World Future Energy Conference held in Abu Dhabi, and predicted that demand for power will increase by 40 percent in the next 20 years, increasing emissions by about 9 percent each year until 2030. The report also predicted that in 2030, fossil fuels will remain the predominant energy source, and account for nearly 80 percent of demand. “Oil still leads, but natural gas moves into second place.” As for electricity, ExxonMobil scientists wrote, “nuclear and renewable fuels will see strong growth. . . By 2030, about 40 percent of the world's electricity will be generated by nuclear and renewable fuels.” The report suggests that by 2030, demand in the United States for foreign oil will have diminished considerably, with developing countries pumping carbon dioxide (CO2) into the atmosphere at the highest rate.

For additional information see: The Guardian

Shrinking Ice Cover in the Arctic Doubles Loss of Reflectivity

On January 18, research published in the journal Nature Geoscience found that the loss of solar reflectivity due to declining sea ice and snow cover is more than double what climate models previously estimated. The analysis covered a 30-year period of the Northern Hemisphere’s albedo feedback, a process by which sunlight is reflected off of light surfaces back into space, which helps to cool the Earth. The findings suggest that the cryosphere, the collective portion of the Earth’s surface where water is in solid form as sea ice, glaciers, and snow cover, is reflecting less energy back into space and exposing ground and water, both dark surfaces that absorb heat, leading to warming and thus more melting of the reflective surfaces. Lead author of the study, Mark Flanner, said, “The conclusion is that the cryosphere (areas of ice and snow) is both responding more sensitively to, and also driving, stronger climate change than thought.” This amplification of the warming has never been measured in climate models, but the study estimated that each degree Celsius rise in temperatures would translate into a decline in reflected solar energy of between 0.3 and 1.1 watts per square meter from the Northern Hemisphere’s cryosphere. Researchers noted that new climate models with a better representation of snow and ice will be released this year.

For additional information see: Science Daily, Reuters

New Measurement of Sun’s Energy Improves Accuracy of Climate Change Estimates

On January 14, a study published in Geophysical Research Letters on solar energy included a new measurement of the amount of solar radiation that hits Earth. Earth-based monitors have measured solar radiation, referred to as total solar irradiance (TSI), for the past 32 years but had different measurements which had to be calibrated off each other to determine TSI. This new value, established from instruments on a NASA spacecraft, is lower than what previous calculations estimated. Researchers were able to corroborate the new measurement at a new calibration facility. Researchers said that the new findings will aid climate science by understanding with better accuracy how much the sun contributes to the planet’s warming. "Scientists estimating Earth's climate sensitivities need accurate and stable solar irradiance records to know exactly how much warming to attribute to changes in the sun's output, versus anthropogenic or other natural forcings,” said co-author Judith Lean of the Naval Research Laboratory. Lean has now adjusted her climate model using the new TSI value and estimates that solar variability produces about 0.1 degrees Celsius global warming during the 11-year solar cycle. (my added emphasis)

For additional information see: New York Times, SiFy, Science Daily, Study

New Report Shows UN Forest Protection Efforts Ineffective

On January 23, a report issued by the International Union of Forest Research Organizations (IUFRO) found that international accords to slow deforestation and protect vulnerable forests were too limited in scope, and have had little success. Worldwide, 10 percent of carbon emissions are from deforestation, and from 2000 to 2009, 32 million acres of forest have been subject to deforestation. The report argued that too much attention was being placed on forests as major stores of carbon dioxide (CO2), the main greenhouse gas (GHG) blamed for global warming, and not on underlying causes of deforestation such as heightened demand for crops and biofuels. The report suggested that the United Nations-backed initiative, Reduced Emissions from Deforestation and forest Degradation (REDD), should focus more on supporting regional efforts to save forests, rather than seeking a standard global solution. IUFRO called for greater efforts to aid indigenous peoples whose livelihoods depend on forests. The assessment is being released as the United Nations launches the International Year of Forests in New York.

For additional information see: Reuters, Science Daily, AFP

Canadian Panel Calls for Climate Change Legislation

On January 25, a Canadian think tank issued a report saying that Canada should progress with a domestic greenhouse gas (GHG) emissions trading system regardless of whether the United States takes similar steps. The National Roundtable on the Environment and the Economy, the government-appointed panel that handles environmental issues, said that by taking measures to tackle climate change, Canada gets “ahead of the curve,” and ensures that economic impacts on Canada are manageable and that Canada makes sustained progress toward achieving its 2020 carbon emissions target of 17 percent below 2005 levels. Lawmakers and industry participants have put pressure on the Canadian government to act without U.S. participation in order to reach their goal within the given time frame. The panel urged the government to pass cap-and-trade legislation that would ensure that the price of carbon never exceed C$30 (US$30.13) price per ton of carbon to ensure that Canada remains competitive with the United States. The panel’s proposed approach “would walk a middle line between harmonizing with the United States on carbon price and on emission reduction targets, balancing competitiveness and environmental concerns,” according to the report.

For additional information see: The Star, Power-Gen Worldwide

U.K. Report Warns of Global Food Shortages, Need for Sustainability

On January 24, a major report published by the U.K.-based think tank Foresight warned that the global food supply is not enough to satisfy booming demand, as the population continues to expand and resources are not being replaced as quickly as they are being consumed. The report, titled “Global Food and Farming Futures,” concluded that the entire agricultural system must undergo a massive overhaul to bring sustainability center stage and end world hunger. The report found that water and energy supplies may struggle to keep up with demand due to climate change, and suggested developing a strategy to avoid food shortages that could damage economic growth and lead to international tensions or conflicts. Some of the proposed strategies include minimizing waste, changing personal diet, reducing subsidies and trade barriers, linking food and agricultural policy to climate change mitigation, and exploring genetically modified organisms (GMO).

For additional information see: Bloomberg, Business Green, Report

Greenhouse Gas Emissions Increasingly Affect Stock Value

On January 25, a study published by professors at Haas School of Business at University of California-Davis and the University of Otago in New Zealand found that potential investors have taken a greater interest in companies’ greenhouse gas (GHG) emissions disclosures, which indicates the amount of emissions is an important factor in the valuation of their stocks. The researchers analyzed data on firms listed in Standard & Poor’s 500 from 2006-2009, and on Canada’s top 200 publicly-traded firms from 2005-2009, and found that companies with high carbon emissions had lower valued stocks, especially with regard to firms in the energy industry. The research tracked 1400 instances of firms that filed formal notices and press releases around events that would impact climate change, and found that markets responded almost immediately, with stock values adjusting on the same day as the formal disclosures. The researchers presumed that this was due to investors feeling that a company’s environmental footprint will have an impact on its long-term costs dealing with mitigation, regulation, and taxes, and thus its profitability. Currently, the U.S. Securities and Exchange Commission (SEC) does not require that all companies report their GHG emissions, but this may change if the SEC validates this study’s findings.

For additional information see: International Business Times

Methane Gas Emissions from Rivers and Lakes Underestimated

On January 22, a study published in the journal Science found that the amount of methane gas, a greenhouse gas (GHG) that contributes to climate change, naturally released from freshwater areas is much higher than scientists previously estimated. The international team of scientists discovered that methane released from rivers and lakes changes the net absorption of GHGs by natural land environments by at least 25 percent, since earlier calculations of GHG absorption did not account for natural emissions of methane from inland water sources. According to John Downing, a professor at Iowa State University and co-author of the study, the team’s findings show scientists that the GHG-absorbing properties of forests and agricultural lands may not “get us as far ahead as we thought” considering methane’s additional contribution to the GHG budget.

For additional information see: Ames Tribune, Study

Greenland Ice Sheet Experienced Record Melting in 2010

On January 21, a study published in Environmental Research Letters showed that the Greenland Ice Sheet experienced record melting in 2010, which is expected to contribute to sea level rise in the future. The study found that 2010’s melt season was up to 50 days longer than average in some areas, starting significantly earlier at the end of April and lasting until mid-September. Dr. Marco Tedesco and co-authors studied surface temperature anomalies across the Greenland Ice Sheet and measurements of surface melting from various data sources. Greenland’s capital had the warmest spring and summer temperatures since records began in 1873. Summer temperatures in 2010 were 3° Celsius above average and there was reduced snowfall. According to Tedesco, the exposure of bare ice to lengthy periods of sunlight contributed to the record melting, since bare ice absorbs more solar radiation than snow. In related news, a U.K.-led study published in the journal Nature found that some Greenland glaciers retreat more slowly in warm summers than in cooler ones, suggesting that the ice may be more resistant to climate change than previously thought. The scientists found that in the warmest summers, the rate of retreat of the glaciers stalled early in the season. They explained that hot weather causes so much meltwater to collect that instead of lubricating the glacier flow, it simply runs off in channels below the ice, causing a pressure drop that leads to reduced ice speeds. The researchers emphasized, however, that the Greenland ice cap is still vulnerable to climate change, and continually loses ice to the sea.

For additional information see: Science Daily, BBC, Science Daily, Study

Changing Climate Threatens Tree Species Survival

On January 24, a study published in Ecology Letters found that many tree species that depend on wind for seed dispersion could become extinct due to climate change. The research focused on the influence of increased levels of atmospheric carbon dioxide (CO2) and changes in wind speed on the production and dispersion of tree seeds. The study found that elevated levels of CO2 causes higher seed production and earlier maturation in trees, which would give rise to faster seed spread in the future. However, according to an author of the study, their research “indicates that the natural wind-driven spread of many species of trees will increase, but will occur at a significantly lower pace than that which will be required to cope with the changes in surface temperature.” As a result, the researchers predict the composition of trees in future forests will change. The research calls for action to ensure the proper dispersal of seeds in order to prevent losing the valuable services these trees offer to humans.

For additional information see: Science Daily, Study

Coral Reefs Moving North at Rapid Pace

On January 21, a study of coral reefs around Japan published in Geophysical Research Letters found that several species of coral have migrated from the subtropics to temperate climate zones in the last 80 years. The study found that four out of nine common coral species had migrated northward, with two traveling to temperate waters. The data confirmed what scientists and fishermen have suspected for years, and it predicted that some coral species will rapidly migrate in response to warmer ocean temperatures. A few of the species examined migrated 8.7 miles per year, while a sample of land-traveling animals migrate an average of only 0.4 miles per year. Over the course of 80 years, some corals will migrate nearly 700 miles. In related news, on January 21, research published in Ecology by Australian scientists found that the key to preserving the world’s coral reefs lies in understanding how newborn coral larvae disperse across oceans, settle, and grow on new reefs as climate change occurs. The scientists studied the dispersal patterns, survival and settlement rates of larvae from various coral species. The authors hope that the study will aid in the management of existing coral reefs threatened by ocean warming, acidification, and pollution. The scientists measured the survival rates of coral larvae, the ability for larvae to settle, and dispersal and settlement rates to include in their revised models, which provide hope that coral species would be able to migrate in order to adapt to climate change. According to the researchers, the models indicate that more larvae than scientists thought should settle close to home, and that a small portion of “stellar performers” can survive for longer and travel further.

For additional information see: Science News, Red Orbit, Study

Natural Gas May Harm Environment More than Previously Thought

On January 25, the Environmental Protection Agency (EPA) published a new estimate of the pollution from natural gas power plants, and found that natural gas may be as little as 25 percent cleaner than oil and coal, and perhaps even less. Previous estimates pegged natural gas as having about 50 percent less greenhouse gas (GHG) emissions than coal. The research updates earlier EPA literature on the subject, which had not included life-cycle methane emissions, and estimated that the amount of methane gas released during the natural gas production process, through leaks from loose pipe fittings and venting from gas wells, is double what the EPA previously reported in April 2010. Methane levels from hydraulic fracturing, a popular new method of extracting natural gas from previously unobtainable sources, of shale gas are 9,000 times higher than previously thought, according to the new analysis. Natural gas still has an environmental advantage over oil and coal, but the margin of benefit is smaller.

For additional information see: ProPublica

Several Bills Introduced to Block EPA Climate Rules

In the first week of February, several Senate and House Republicans introduced bills to limit or prevent the Environmental Protection Agency’s (EPA) authority in climate change matters. Sen. John Barrasso (R-WY) introduced broad legislation that would prevent the EPA from regulating greenhouse gases (GHG) in any of its actions to address climate change. According to Barrasso, controlling emissions would harm the economy and stifle job growth. The bill would forbid the use of landmark federal legislation such as the Clean Air Act and the Clean Water Act to implement laws concerning climate change. It would also overturn the EPA’s 2009 finding that carbon dioxide (CO2) and other GHGs pose a threat to public and environmental health. The bill included one concession to allow new vehicle emissions standards to go forward, but it would shift the responsibility of managing them to the Department of Transportation. As of February 4, the bill has ten Republican co-sponsors. Rep. Fred Upton (R-MI), House Energy and Commerce Committee Chairman, also introduced draft legislation that would prohibit the EPA from regulating GHGs under the Clean Air Act. Officials said that the bill would nullify the EPA’s finding that GHGs are a danger to public health, and strip the agency of the authority to use the law in any future attempts to regulate emissions from polluting firms. In a less aggressive measure to block federal climate rules, Sen. Jay Rockefeller (D-WV) introduced a bill to delay the EPA’s authority to regulate GHG emissions for two years. Rockefeller’s bill was co-sponsored by six Democrats.

For additional information see: The Hill, New York Times, The Hill, The Wall Street Journal, AP, Barrasso Press Release, Upton Press Release

Republican Group Seeks to Eliminate United Nations Climate Change Panel

On February 2, the Republican Study Committee released a proposal to cut $2.5 trillion in spending. Among the key cuts to energy efficiency, renewable energy, and clean transportation, is $12.5 million in annual funding to the United Nations Intergovernmental Panel on Climate Change (IPCC). The funding supports costs for organizing research from scientists around the world who work without direct compensation for the time and effort they spend in the process of publishing IPCC documents. The intent of the IPCC is to help the public as well as policymakers understand climate change. According to the IPCC, however, the projected 2011 budget totals just under $10 million and historically U.S. funding fluctuated between $200,000 and $5.6 million.

For additional information see: Sustainable Business

UN Secretary General Calls on EU, United States, and Big Business to Lead on Climate

On January 31, United Nations (UN) secretary-general Ban Ki-moon issued a demand that the United States and the EU lead global efforts to curb climate change regardless of whether other countries act. Ban told the World Economic Forum summit in Davos, Switzerland that the countries that had led the industrial revolution had a responsibility to spearhead the development of a low carbon economy, and warned that the world’s belief in “consumption without consequences” had to change immediately. Ban joined other political leaders, such as Presidents Felipe Calderon of Mexico and Jacob Zuma of South Africa, in their concern that the United States should take stronger leadership in climate crisis given its position as a world superpower and a leading carbon dioxide (CO2) emitter. In addition to calling on Europe and the United States to lead the climate change battle, Ban also called upon businesses to play a more central role in curbing climate change by launching Global Compact LEAD, a UN program to encourage businesses to share their sustainable practices and expertise.

For additional information see: Business Green

Heat-Related Deaths Could Increase by Mid-Century

On January 28, researchers at the Environmental Protection Agency (EPA) published a study in the journal Environmental Science and Technology that found that the number of heat-related deaths in the United States could increase substantially in the next few decades due to rising temperatures from climate change. According to researchers, an estimated 3,500 to 27,000 additional deaths could occur each year from extreme hot weather by mid-century, compared to 3,400 total deaths between 1999-2003. The study used a computer model to analyze how a change in temperature over time could impact human health. The researchers divided the United States into grid cells, and then adjusted results from NASA’s global circulation model to estimate temperatures for each cell for two time periods, 1999-2003 and 2048-2052. The NASA model measured temperatures in the future scenario as roughly 2°C higher. Researchers then used results from five previous epidemiological studies that measured the risk of dying associated with changes in temperature to determine heat-related health effects. The authors acknowledged that their study did not account for several variables, such as how people adapt to hot weather.

For additional information see: Chemical & Engineering News, Study

Arctic Ocean Warmest in 2,000 Years

On January 28, a study published in the journal Science found that the current flowing from the North Atlantic into the Arctic Ocean is warmer now than it has been any time in the past 2,000 years. The study provided new evidence that human activities might be causing the recent warming, since temperatures in the past never reached these heights, even during warm periods from increased solar energy output. However, “it doesn’t necessarily prove that the change that we see is man-made, but it does strongly point toward this being an unusual event,” said Thomas Marchitto, a co-author of the study. The scientists found that the Fram Strait, which carries Atlantic ocean heat to the Arctic between Greenland and Svalbard, reached temperatures “well outside the natural bounds,” noting that summer water temperatures have risen an average of 5.2°C from 1890-2007, and about 3.4°C in the previous 1,900 years. The scientists used both climate records and data from sediment cores dating back 2,000 years to determine water temperatures. The authors expected the Arctic Ocean to be free of ice in summers of coming decades, disrupting hunting patterns of indigenous peoples and animals.

For additional information see: New York Times, Reuters, University of Colorado

Two “Once-in-a-Century” Amazon Droughts Concern Scientists

On February 4, a study published in Science found that the 2010 Amazon drought was more widespread and devastating to the region’s rainforests than the 2005 drought that was labeled as a “once-in-a-century” occurrence. The UK-Brazilian research team also calculated that the carbon impact of the 2010 drought could exceed the 5 billion tons of carbon dioxide (CO2) released from dying trees during the drought of 2005. In both cases, the droughts were linked to unusually warm surface water temperatures in the Atlantic Ocean. The study found that last year’s drought caused rainfall shortages over a 1.16 million square-mile area of forest, as compared to the 2005 drought that reached 734,000 square miles. The 2010 drought was more intense than that of 2005, with increased tree mortality. As a result, the Amazon rainforest may not absorb its annual average 1.5 billion tons of CO2 from the atmosphere, and the dead and dying trees could release more CO2 than the United States emits in a year. The researchers predicted that the droughts have put the vast Amazon rainforest on the verge of a tipping point where instead of absorbing harmful greenhouse gases (GHGs), it will instead release them, speeding up climate change.

For additional information see: Christian Science Monitor, Science Daily, Reuters, Sydney Morning Herald, International Business Times, Study Abstract

Warming Could Reduce Polar Bear Births, Jeopardize Species

On February 8, researchers from the University of Alberta published a study in Nature Communications that linked declining polar bear litter sizes in Hudson Bay with the loss of sea ice. The study found that polar bear species in much of the Arctic will be jeopardized if climate change continues unabated, given projected reductions in the number of newborn cubs. The scientists examined data on the changing length of time that Hudson Bay was frozen over during the winter and early spring, which is the polar bear’s hunting season, and the amount of energy that pregnant females can store before hibernation and birthing. According to the study, an early spring break up of ice cover reduces the females’ hunting season, making it difficult for pregnant females to nourish and support themselves. As a result, energy-deprived pregnant females will either not enter a maternity den or they will naturally abort the birth of a cub. The researchers calculated scenarios to estimate the energetic impacts of a shortened hunting season, and the most conservative finding suggested that with spring break up occurring a month earlier than in the 1990s, 40 to 73 percent of pregnant females will not reproduce. The polar bears of Hudson Bay are the most southerly population of the species, and they are the first to be affected by the warming trend, the report noted.

For additional information see: Science Daily, Study Abstract

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Chad A. Tolman
Coalition for Climate Change Study and Action

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