Studies Link Climate Change to Recent Extreme Weather Events

The Nicholas Institute for Environmental Policy Solutions at Duke University
The Nicholas Institute for Environmental Policy Solutions at Duke University

New research in the Bulletin of the American Meteorological Society finds that climate change influenced the majority of 16 extreme weather events in 2013. Specifically, it found evidence that climate change linked to human causes—particularly burning of fossil fuels—increased the odds of nine extreme events: amplifying temperature in China, Japan, Korea, Australia and Europe; intense rain in parts of the United States and India and severe droughts in New Zealand and California.

“It is not ever a single factor that is responsible for the extremes that we see; in many cases, there are multiple factors,” said Tom Karl, director of National Oceanic and Atmospheric Administration’s (NOAA’s) National Climatic Data Center, of the third NOAA-led annual report to make connections between human-caused climate change and individual extreme weather events.

Twenty groups of scientists conducted independent peer-reviewed studies on the same 16 extreme events occurring on four continents to arrive at their conclusions.

“There is great scientific value in having multiple studies analyze the same extreme event to determine the underlying factors that may have influenced it,” said Stephanie C. Herring of NOAA’s National Climatic Data Center and lead report editor. “Results from this report not only add to our body of knowledge about what drives extreme events, but what the odds are of these events happening again—and to what severity.”

Although the report concludes that the long durations of heat waves “are becoming increasingly likely” due to human-caused climate change, the effects of such change on other types of extremes—California’s drought and extreme rain in Colorado—are less clear.

“Temperature is much more continuous as opposed to precipitation, which is an on/off event,” said Karl. “If you have an on/off event, it makes the tools we have a little more difficult to use.”

Although the NOAA study reached mixed conclusions about the ongoing California drought’s connection to climate change, new research out of Stanford University is a bit more confident. The Stanford study found it is “very likely” that atmospheric conditions associated with the unprecedented drought in the state are linked to human-caused climate change.

“Our research finds that extreme atmospheric high pressure in this region—which is strongly linked to unusually low precipitation in California—is much more likely to occur today than prior to the human emission of greenhouse gases that began during the Industrial Revolution in the 1800s,” said Noah Diffenbaugh, a Stanford climate scientist.

According to the study, these high pressure ridges—currently parked over the Pacific Ocean—are now three times more likely to occur, and as long as high levels of greenhouse gases remain severe, drought will become more frequent.

Emissions from Industrial Facilities Rose Last Year

Reported greenhouse gas emissions from large industrial facilities were 0.6 percent—or roughly 20 million metric tons—higher in 2013 than in the year previous, according to new data from the U.S. Environmental Protection Agency (EPA), which linked the rise to greater coal use for power generation. A large majority of the increase, 13 million metric tons, was from the power sector alone—though overall emissions from power plants are down 9.8 percent since 2010. Reported emissions from the oil and natural gas sector declined 12 percent from 2011 levels, according to the report.

The news comes on the heels of an extension of the public comment period on EPA’s proposed Clean Power Plan, which aims to reduce greenhouse gas emissions from existing power plants, and of new comments by EPA Administrator Gina McCarthy concerning the proposal.

There will be “changes between proposal and final,” said McCarthy. “You may see adjustments in the state levels. You may see adjustments in the framework,” McCarthy noted, referring to the emissions reduction targets the EPA proposed for each state and to the formula used to calculate those targets. The changes could also include updates to the values for nuclear power and natural gas generation.

IEA Says Solar Could Become Dominate Energy Source by 2050

Solar could surpass fossil fuels as the largest source of electricity by mid-century, according to reports issued by the International Energy Agency (IEA). The reports suggests that together solar photovoltaic systems (PV) and concentrating solar power (CSP) could provide 27 percent of the world’s energy by 2050; fossil fuels would account for somewhere between 12 percent and 20 percent.

“The rapid cost decrease of photovoltaic modules and systems in the last few years has opened new perspectives for using solar energy as a major source of electricity in the coming years and decades,” said IEA Executive Director Maria van der Hoeven. “However, both technologies are very capital intensive: almost all expenditures are made upfront. Lowering the cost of capital is thus of primary importance for achieving the vision in these roadmaps.”

By 2050, the IEA said, PV will surge from today’s 150 gigawatts of installed capacity to 4,600 gigawatts, while CSP will increase from 4 gigawatts to 1,000 gigawatts (subscription). These projections are based on the IEA’s expectations that China and the United States will remain top installers for the foreseeable future and that PV will dominate up until 2030.

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.