A new study in the journal Nature offers that for the first time scientists have directly observed an increase in one major greenhouse gas at Earth's surface.
"We see, for the first time in the field, the amplification of the greenhouse effect because there's more CO2 [carbon dioxide] in the atmosphere to absorb what the Earth emits in response to incoming solar radiation," said lead author Daniel Feldman. "Numerous studies show rising atmospheric CO2 concentrations, but our study provides the critical link between those concentrations and the addition of energy to the system, or the greenhouse effect."
Feldman and other researchers from the Lawrence Berkeley National Laboratory and the University of California, Berkeley, measured the amount of infrared heat radiation from the sun reaching Earth's surface and the amount of heat radiation the Earth emits back. Examination of carbon dioxide concentrations from 2000 to 2010 in Alaska and Oklahoma showed the "fingerprint of carbon dioxide" trapping heat in action. Some of the heat from Earth was being blocked by carbon dioxide in the atmosphere -- allowing the researchers to calculate that this effect amounted to two tenths of a watt per square meter of surface warming per decade (22 parts per million between 2000 and 2010).
"The data say what the data say," Feldman said. "They are very clear that the rising carbon dioxide is actually contributing to an increased greenhouse effect at those sites."
Net Zero Emissions: The Business Case
A recently leaked European Union planning document states that "the world's states should commit to a legally binding emissions cut of 60 percent by 2050, with five yearly reviews." Still, many scientists and policy experts want this year's Paris climate talks to aim for net zero emissions. In fact, the latest draft climate agreement, forged a few weeks ago in Geneva, does contain 15 versions of a net zero greenhouse gas (GHG) emissions goal.
Using information in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, the 2014 United Nations Environment Programme's Emissions Gap Report, and other scientific literature, a new briefing note from Climate Analytics details timeframes for that goal. For a 66-percent likelihood of avoiding 2 degrees of warming by century's end, GHG emissions would have to be 40 to 70 percent below 2010 levels by 2050 and would need to reach zero sometime between 2080 and 2100, but energy and industry emissions of CO2 would have to reach zero no later than 2075 and perhaps as soon as 2060.
At the outset of the Geneva talks, The B Team, a group of leaders from the business and nonprofit sectors founded by Sir Richard Branson, referenced the 66-percent chance in endorsing a net zero emissions goal: "The B Team view a 1-in-3 chance of failure as an unreasonable risk scenario carrying significant cost implications, strengthening the business case for achieving net-zero GHG emissions by 2050."
"Momentum is already growing in finance, business and political circles for a net zero goal," wrote Mary Robinson, the United Nations Secretary General's special envoy on climate change, in the foreword to The Business Case for Adopting the Long-Term Goal for Net Zero Emissions, a report published by Track0.org.
EPA Airline Emissions Plan Under Review
The U.S. Environmental Protection Agency (EPA) first proposed the idea of regulating emissions for the airline industry, which accounts for 2 to 3 percent of global greenhouse gas emissions, last year. Media report that the EPA has now sent the White House's Office of Management and Budget its draft conclusion on whether carbon emitted from airplanes is cumulatively harmful to the environment and what the agency might do to restrict emissions.
NBC reports on how a decision to regulate airline emissions could lead to fuel-efficient planes.
Following the White House's review of the document, the EPA could, according to Think Progress, make a proposal to the public as early as May, with a final decision coming in 2016. The Daily Caller, however, reports the EPA has no timeline in mind.
"We don't have a timeline for doing a rule," said an EPA spokeswoman. "For any potential EPA domestic rulemaking to adopt equivalent international standards, EPA would have to propose and then finalize an affirmative endangerment and cause or contribute findings for aircraft greenhouse gas emissions."
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.