Federal climate report finds ‘extreme’ conditions, despite Trump’s cold shoulder

Adrianna Pacheco cools off with Jessica Martinez and her children in Contra Loma Swim Lagoon in Antioch in June. Adrianna Pacheco cools off with Jessica Martinez and her children in Contra Loma Swim Lagoon in Antioch in June. Photo: Leah Millis, The Chronicle Buy photo Photo: Leah Millis, The Chronicle Image 1 of / 1 Caption Close Federal climate report finds ‘extreme’ conditions, despite Trump’s cold shoulder 1 / 1 Back to Gallery

A new federal report could again challenge the Trump administration’s dismissive stance on global warming, finding that last year the planet was hotter than any time in well over a century and witnessed perhaps the most significant climate disruption in modern history.

The annual State of the Climate report, published Thursday by the National Oceanic and Atmospheric Administration, confirmed that 2016 not only set a new mark for heat but broke records for sea-level rise, the amount of ocean ice and snow cover that were lost, and the level of heat-trapping pollutants in the air.

While the study, recognized as the U.S. government’s most comprehensive look at climate, identified varying levels of turbulence across the globe, few spots were immune to the impacts of climate change — and some faced dire threats.

In the United States, 15 weather or climate-related disasters, including drought, wildfire, four inland floods and eight severe storms, caused 138 deaths and $46 billion in damages, the second-biggest bill since record-keeping began in 1980, according to the report.

California shared in the havoc. The state experienced its hottest summer on record last year, the report noted, and saw one of its most severe droughts give way to one of its wettest winters. The report also listed the state as among the nation’s hardest hit by fire.

Going forward, the report’s authors issued a broader warning that increasing temperatures in California and elsewhere would mean less snowfall and tighter water supplies as well as flooding in coastal areas amid rising oceans.

“When you set record after record after record, it’s very extreme and it’s cause for concern,” said Jessica Blunden, a NOAA climatologist and lead editor of the new report.

Though climate change has rarely been documented in such detail, the report stopped short of linking the problem to what scientists agree is the leading cause — human activity, such as burning coal and gasoline. The agency said the aim of the report was purely “diagnostic.”

Earlier this week, however, a draft copy of the National Climate Assessment produced by 13 federal agencies made an unequivocal connection between weather extremes and human-produced greenhouse gases.

President Trump has not only denied the link, calling climate change a hoax, but reversed course on U.S. policy on greenhouse-gas emissions. This month, he formally notified the United Nations that the U.S. will withdraw from the Paris climate agreement, reneging on the nation’s commitment to reducing heat-trapping pollutants.

“Reality does not seem to play a very significant role in the way this administration is responding to the threat of climate change,” said Peter Gleick, chief scientist and co-founder of the Pacific Institute, an Oakland think tank that studies water issues, who did not contribute to the report. “I don’t know what else the scientific community can say or what the planet can say that will finally get the federal government to act. As a climate scientist, it’s frustrating.”

Last year was the third consecutive year of record-breaking heat in 137 years of tracking temperatures , according to the new 299-page report, which was written by 450 scientists in more than 60 nations.

The rising mercury, the report said, stems from last year’s El Niño weather pattern in the Pacific Ocean as well as the planet’s long-term warming trend. Globally, temperatures were up almost a full degree over the average measured from 1981 to 2010.

The spike was greatest in the Arctic, where temperatures were 3.6 degrees above the 1981-2010 average and 6.3 degrees higher than they were in 1900.

Meanwhile, the world’s alpine glaciers retreated for the 37th straight year, according to the report, while springtime snow cover dipped to new lows in many parts of the world.

Globally, sea level hit a record high last year, marking the sixth consecutive annual increase. The oceans have risen an average of 0.13 of an inche per year over the past two decades, the report stated.

Greenhouse-gas concentrations also were up. Carbon dioxide, methane and nitrous oxide, all drivers of atmospheric warming, recorded new highs last year, with carbon dioxide surpassing a milestone 400 parts per million for the first time in recent history. The last time carbon dioxide levels were as great was probably more than 800,000 years ago, long before modern humans roamed Earth.

While the findings in Thursday’s report were limited to 2016, NOAA scientists said there’s been little, if any, letup in climate trends this year.

“Global temperature appears to be running behind 2016, comparable to 2015,” said Deke Arndt, one of the report’s co-authors. “But 2017 has not shown any dramatic reversal of course.”

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander