Scientists at the National Snow and Ice Data Center (NSIDC) said on Monday that Arctic sea ice cover of 5.607 million square miles on March 24 represented the lowest winter maximum since records began in 1979. That's 5,000 square miles less than last year's record low. Contributing to the ice extent loss were record high air temperatures and relatively warm seawater.
"It is likely that we're going to keep seeing smaller wintertime maximums in the future because in addition to a warmer atmosphere, the ocean has also warmed up," said Walt Meier, a sea ice scientist at NASA's Goddard Space Flight Center. "That warmer ocean will not let the ice edge expand as far south as it used to. Although the maximum reach of the sea ice can vary a lot each year depending on winter weather conditions, we're seeing a significant downward trend, and that's ultimately related to the warming atmosphere and oceans."
After this winter's record ice lows, scientists expect the Arctic could be ice-free in the summer months in the next few decades.
"Sometime in the 2030s or 2040s time frame, at least for a few days, you won't have ice out there in the dead of summer," said John Walsh, chief scientist of the International Arctic Research Centre. "The balance is shifting to the point where we are not going back to the old regime of the 1980s and 1990s. Every year has had less ice cover than any summer since 2007. That is nine years in a row that you would call unprecedented. When that happens you have to start thinking that something is going on that is not letting the system go back to where it used to be."
The effects of diminishing sea ice may not be limited to just the Arctic.
"The Arctic is in crisis," said Ted Scambos, NSIDC lead scientist. "Year by year, it's slipping into a new state, and it's hard to see how that won't have an effect on weather throughout the Northern Hemisphere."
A new paper in the Journal of Climate linked the vanishing Arctic sea ice, along with other sea ice melting and global sea-level rise, to climate change. The authors, who used computer models and field measurements to explore whether Arctic sea ice loss has contributed to melting of the Greenland ice sheet, say that melting Arctic sea ice can block cold, dry Canadian air, increasing the flow of warm, moist air over Greenland and contributing to extreme heat events and surface ice melting. If the Greenland ice sheet completely melted, the paper says, the global sea level would rise about 20 to 23 feet.
U.S. Environmental Protection Agency Files Brief Defending Clean Power Plan
The D.C. Circuit is set to begin hearing oral arguments challenging the Clean Power Plan--the Obama administration's rule to limit greenhouse gas emissions from the existing fleet of fossil fuel-fired power plants--in June. On Monday, the U.S. Environmental Protection Agency filed its defense of the Clean Power Plan, telling the court that the rule is well within the bounds of its authority (subscription). Dozens of states and industry groups last month called the rule a "breathtaking expansion" of the power Congress gave the EPA--with the Clean Air Act--to regulate greenhouse gas emissions.
"The rule reflects the eminently reasonable exercise of EPA's recognized statutory authority," the EPA brief says. "It will achieve cost-effective [carbon dioxide] reductions from an industry that has already demonstrated its ability to comply with robust pollution-control standards through the same measures and flexible approaches. The rule fulfills both the letter and spirit of Congress's direction."
Renewable Energy Investment Outpaced Other Technologies: Study
Investment in renewable energy generation last year was higher than in new coal- and gas-fired power plants, according to a new report from the Frankfurt School-United Nations Environment Programme collaborating Centre for Climate & Sustainable Energy Finance and Bloomberg New Energy Finance (BNEF). In fact, renewables added more to global energy generation capacity than all other technologies combined--though they still only account for 10 percent of global electricity production.
"Global investment in renewables capacity hit a new record in 2015, far outpacing that in fossil fuel generating capacity despite falling oil, gas, and coal prices," said Michael Liebreich, chair of the BNEF advisory board. "It has broadened out to a wider and wider array of developing countries, helped by sharply reduced costs and by the benefits of local power production over reliance on imported commodities."
All investment in renewables--which includes new renewable energy capacity as well as early-stage technology, research and development--totaled $286 billion in 2015. That's roughly 3 percent higher than the previous record set back in 2011.
Countries contributing some of the most to these numbers included China, which in 2015 invested $102.9 billion (a 17 percent increase from 2014), representing 36 percent of the global investment total; Chile ($3.4 billion, a 151 percent increase), India ($10.2 billion, a 22 percent increase), Mexico ($4 billion, a 105 percent increase) and South Africa ($4.5 billion, a 329 percent increase).
The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University's Nicholas Institute for Environmental Policy Solutions.