Debra Kahn & Anne C. Mulkern, SCIENTIFIC AMERICAN
As wildfires engulf nearly 170,000 acres of Northern California wine country, questions are swirling about the role of climate change in causing damage of historic proportions.
The fires, which started late Sunday night in the hills of Napa and Sonoma counties, quickly ballooned to 22 separate conflagrations in eight counties, killing at least 21 people by Tuesday evening. The Tubbs Fire, in Sonoma County, has been responsible for at least 11 deaths so far, making it the sixth-deadliest fire in state history. Nearly 300 people are still reported missing and 25,000 have been evacuated in Sonoma County alone, with more than 3,500 homes and businesses destroyed.
Strong winds were responsible for the fires’ quick incursion into urban areas, but months of record-high temperatures, preceded by heavy rainfall last winter, also fueled the destructive power of the fire that burned through the region, climate experts said.
Read more at: Scientists See Climate Change in California’s Wildfires – Scientific American
The average temperature in the United States has risen rapidly and drastically since 1980, and recent decades have been the warmest of the past 1,500 years, according to a sweeping federal climate change report awaiting approval by the Trump administration.
The draft report by scientists from 13 federal agencies, which has not yet been made public, concludes that Americans are feeling the effects of climate change right now. It directly contradicts claims by President Trump and members of his cabinet who say that the human contribution to climate change is uncertain, and that the ability to predict the effects is limited.
“Evidence for a changing climate abounds, from the top of the atmosphere to the depths of the oceans,” a draft of the report states. A copy of it was obtained by The New York Times.
The authors note that thousands of studies, conducted by tens of thousands of scientists, have documented climate changes on land and in the air. “Many lines of evidence demonstrate that human activities, especially emissions of greenhouse (heat-trapping) gases, are primarily responsible for recent observed climate change,” they wrote.
The report was completed this year and is a special science section of the National Climate Assessment, which is congressionally mandated every four years. The National Academy of Sciences has signed off on the draft report, and the authors are awaiting permission from the Trump administration to release it.
Chris Mooney and Juliet Eilperin, THE WASHINGTON POST
The Environmental Protection Agency announced Friday evening that its website would be “undergoing changes” to better represent the new direction the agency is taking, triggering the removal of several agency websites containing detailed climate data and scientific information.
One of the websites that appeared to be gone had been cited to challenge statements made by the EPA’s new administrator, Scott Pruitt. Another provided detailed information on the previous administration’s Clean Power Plan, including fact sheets about greenhouse gas emissions on the state and local levels and how different demographic groups were affected by such emissions.
The changes came less than 24 hours before thousands of protesters were set to march in Washington and around the country in support of political action to push back against the Trump administration’s rollbacks of former president Barack Obama’s climate policies.
Read more at: EPA website removes climate science site from public view after two decades – The Washington Post
Alicia Chang, ASSOCIATED PRESS
A decade ago, California vowed to dramatically slash greenhouse gas emissions by 2020.With the nation’s most populous state on pace to meet that target, Gov. Jerry Brown on Thursday charted a new goal to further cut carbon pollution by extending and expanding the landmark climate change law.
It will “keep California on the move to clean up the environment,” Brown said in a Los Angeles park before signing a pair of bills that survived heavy opposition from the oil industry, business groups and Republicans.
Experts said going forward will be more challenging because the new goal — to reduce emissions 40 percent below 1990 levels by 2030 — is considerably more ambitious and many of the easy solutions have been employed.
“The long and the short of it is that meeting the goal will require sustained regulatory effort across all sectors of the economy,” said Ann Carlson, a professor of environmental law at the University of California, Los Angeles.
California is on track to meet the 2020 climate goal that called for reducing emissions to 1990 levels by restricting the carbon content of gasoline and diesel fuel, encouraging sales of zero-emission vehicles and imposing a tax on pollution.
The state plans to build on that foundation and ramp up other efforts including increasing renewable electricity use, boosting energy efficiency in existing buildings and putting 1.5 million zero-emissions vehicles on the road, according to the California Air Resources Board, which is in charge of climate policy.
Read more at: California extends most ambitious US climate change law | The Press Democrat
Justin Gillis, THE NEW YORK TIMES
Global warming caused by human emissions has most likely intensified the drought in California by 15 to 20 percent, scientists said on Thursday, warning that future dry spells in the state are almost certain to be worse than this one as the world continues to heat up.
Even though the findings suggest that the drought is primarily a consequence of natural climate variability, the scientists added that the likelihood of any drought becoming acute is rising because of climate change. The odds of California suffering droughts at the far end of the scale, like the current one that began in 2012, have roughly doubled over the past century, they said.
“This would be a drought no matter what,” said A. Park Williams, a climate scientist at the Lamont-Doherty Earth Observatory of Columbia University and the lead author of a paper published by the journal Geophysical Research Letters. “It would be a fairly bad drought no matter what. But it’s definitely made worse by global warming.”
The National Oceanic and Atmospheric Administration also reported Thursday that global temperatures in July had been the hottest for any month since record-keeping began in 1880, and that the first seven months of 2015 had also been the hottest such period ever. Heat waves on several continents this summer have killed thousands of people.
Read more at: California Drought Is Made Worse by Global Warming, Scientists Say – The New York Times
Tom Randall, BLOOMBERG.COM
Record rains fell in California this week. They’re not enough to change the course of what scientists are now calling the region’s worst drought in at least 1,200 years.
Just how bad has California’s drought been? Modern measurements already showed it’s been drier than the 1930s dustbowl, worse than the historic droughts of the 1970s and 1980s. That’s not all. New research going back further than the Viking conquests in Europe still can’t find a drought as bad as this one.
To go back that far, scientists consulted one of the longest records available: tree rings. Tighter rings mean drier years, and by working with California’s exceptionally old trees, researchers from University of Minnesota and Woods Hole Oceanographic Institute were able to reconstruct a chronology of drought in southern and central California. They identified 37 droughts that lasted three years or more, going back to the year 800.
None were as extreme as the conditions we’re seeing now.
One of the oddities of this drought is that conditions aren’t just driven by a lack of rainfall. There have been plenty of droughts in the past with less precipitation. (The drought of 1527 to 1529, for example, was killer.) What makes this drought exceptional is the heat. Extreme heat.
Higher temperatures increase evaporation and help deplete reservoirs and groundwater. The California heat this year is like nothing ever seen in modern temperature records. The chart above shows average year-to-date temperatures in the state from January through October for each year since 1895.
Read more via California’s ‘Hot Drought’ Ranks Worst in at Least 1,200 Years – Bloomberg.