One government scientist who worked on the report, Katharine Hayhoe, a professor of political science at Texas Tech University, called the conclusions among “the most comprehensive climate science reports” to be published. Another scientist involved in the process, who spoke to The New York Times on the condition of anonymity, said he and others were concerned that it would be suppressed.
The White House and the Environmental Protection Agency did not immediately return calls or respond to emails requesting comment on Monday night.
The report concludes that even if humans immediately stopped emitting greenhouse gases into the atmosphere, the world would still feel at least an additional 0.50 degrees Fahrenheit (0.30 degrees Celsius) of warming over this century compared with today. The projected actual rise, scientists say, will be as much as 2 degrees Celsius.
A small difference in global temperatures can make a big difference in the climate: The difference between a rise in global temperatures of 1.5 degrees Celsius and one of 2 degrees Celsius, for example, could mean longer heat waves, more intense rainstorms and the faster disintegration of coral reefs.
Among the more significant of the study’s findings is that it is possible to attribute some extreme weather to climate change. The field known as “attribution science” has advanced rapidly in response to increasing risks from climate change.
The E.P.A. is one of 13 agencies that must approve the report by Aug. 18. The agency’s administrator, Scott Pruitt, has said he does not believe that carbon dioxide is a primary contributor to global warming.
“It’s a fraught situation,” said Michael Oppenheimer, a professor of geoscience and international affairs at Princeton University who was not involved in the study. “This is the first case in which an analysis of climate change of this scope has come up in the Trump administration, and scientists will be watching very carefully to see how they handle it.”
Advertisement
Continue reading the main story
Scientists say they fear that the Trump administration could change or suppress the report. But those who challenge scientific data on human-caused climate change say they are equally worried that the draft report, as well as the larger National Climate Assessment, will be publicly released.
“The National Climate Assessment seems to be on autopilot because there’s no political that has taken control of it,” said Myron Ebell, a senior fellow at the Competitive Enterprise Institute. He was referring to a lack of political direction from the Trump administration.
The report says significant advances have been made linking human influence to individual extreme weather events since the last National Climate Assessment was produced in 2014. Still, it notes, crucial uncertainties remain.
It cites the European heat wave of 2003 and the record heat in Australia in 2013 as specific episodes where “relatively strong evidence” showed that a man-made factor contributed to the extreme weather.
In the United States, the authors write, the heat wave that broiled Texas in 2011 was more complicated. That year was Texas’ driest on record, and one study cited in the report said local weather variability and La Niña were the primary causes, with a “relatively small” warming contribution. Another study had concluded that climate change made extreme events 20 times more likely in Texas.
Based on those and other conflicting studies, the federal draft concludes that there was a medium likelihood that climate change played a role in the Texas heat wave. But it avoids assessing other individual weather events for their link to climate change. Generally, the report described linking recent major droughts in the United States to human activity as “complicated,” saying that while many droughts have been long and severe, they have not been unprecedented in the earth’s hydrologic natural variation.
Worldwide, the draft report finds it “extremely likely” that more than half of the global mean temperature increase since 1951 can be linked to human influence.
In the United States, the report concludes with “very high” confidence that the number and severity of cool nights have decreased since the 1960s, while the frequency and severity of warm days have increased. Extreme cold waves, it says, are less common since the 1980s, while extreme heat waves are more common.
The study examines every corner of the United States and finds that all of it was touched by climate change. The average annual temperature in the United States will continue to rise, the authors write, making recent record-setting years “relatively common” in the near future. It projects increases of 5.0 to 7.5 degrees Fahrenheit (2.8 to 4.8 degrees Celsius) by the late century, depending on the level of future emissions.
Advertisement
Continue reading the main story
It says the average annual rainfall across the country has increased by about 4 percent since the beginning of the 20th century. Parts of the West, Southwest and Southeast are drying up, while the Southern Plains and the Midwest are getting wetter.
With a medium degree of confidence, the authors linked the contribution of human-caused warming to rising temperatures over the Western and Northern United States. It found no direct link in the Southeast.
Additionally, the government scientists wrote that surface, air and ground temperatures in Alaska and the Arctic are rising at a frighteningly fast rate — twice as fast as the global average.
“It is very likely that the accelerated rate of Arctic warming will have a significant consequence for the United States due to accelerating land and sea ice melting that is driving changes in the ocean including sea level rise threatening our coastal communities,” the report says.
Human activity, the report goes on to say, is a primary culprit.
The study does not make policy recommendations, but it notes that stabilizing the global mean temperature increase to 2 degrees Celsius — what scientists have referred to as the guardrail beyond which changes become catastrophic — will require significant reductions in global levels of carbon dioxide.
Nearly 200 nations agreed as part of the Paris accords to limit or cut fossil fuel emissions. If countries make good on those promises, the federal report says, that will be a key step toward keeping global warming at manageable levels.
Mr. Trump announced this year that the United States would withdraw from the Paris agreement, saying the deal was bad for America.
CARACAS, Venezuela — As Venezuela’s political crisis spins further out of control, many are looking to the military to see if its once-unflinching loyalty to the socialist revolution might be fraying.
On Sunday morning, Venezuelans awoke to news that a small group of armed men tried to take over a major military base in the central city of Valencia after a long-mutinous national guard captain appeared in a video calling for rebellion.
The government said what it described as a “terrorist attack” led mostly by civilians dressed in fatigues and deserted officers, not active troops, was quickly put down and seven people were arrested. It wasn’t clear how much support existed for the so-called “Operation David,” but dozens of civilians startled by the sound of gunfire poured into the streets singing Venezuela’s national anthem to back the rebels.
Many people wonder whether the tension-filled incident could foreshadow a bigger uprising to come from a military with a long history of rebellion and whose troops — like many Venezuelans — are increasingly caught up in the nation’s economic and political crisis.
Analysts say that such a scenario is unlikely for now.
While signs of disgruntlement are growing as security forces come under a barrage of rocks and Molotov cocktails during almost-daily anti-Maduro protests, soldiers also fear persecution under an opposition government. In addition, they face risks that any plans for a secret uprising would be found out.
“They feel trapped,” said former army Gen. Hebert Garcia Plaza, a former Maduro minister. Since seeking exile in Washington in 2015 following accusations of corruption by Maduro, he has emerged as a sought-after filter of information for journalists, the opposition and, increasingly he says, distraught soldiers.
“There’s lots of unease, but they can’t provoke a political change without a clear horizon of what comes after Maduro,” Garcia Plaza said.
Venezuela’s military accumulated unmatched power and privilege in the past two decades of socialist rule, and Maduro has been increasingly relying on the armed forces as his own grip on power weakens. Last week, with the support of top generals, he plowed forward with a plan to seat an all-powerful assembly mandated with rewriting the constitution. Political opponents and dozens of foreign governments consider it an illegitimate power grab that will strip Venezuela of its last vestiges of democracy.
The opposition is urging the military to switch loyalties and pressure Maduro to cede to its demands, including freeing hundreds of political prisoners and setting a timetable for presidential elections. But many in the military, especially higher-ranking officers, have already hitched their fate to the revolution.
Following a 2002 coup, then-President Hugo Chavez, himself a former tank commander, carried out a deep purge of the military and promoted loyal officers to top positions in the government.
Maduro has expanded the military’s political power even further, giving them control of key sectors of the economy, such as food importation. He also rewarded soldiers with pay raises and bonuses that are the envy of civilians struggling amid triple-digit inflation and widespread shortages.
Even before the ballots were counted in the July 30 election for the constitutional assembly, Defense Minister Gen. Vladimir Padrino Lopez went in front of the cameras accompanied by the top military brass to celebrate the results as a defeat for imperialism.
Despite the outward loyalty, some cracks began to appear even before Sunday’s attack. At least 106 members of the armed forces, some of them junior officers, have been jailed for alleged crimes such as rebellion and treason since protests began in April, according to the lists provided by an army official on the condition of anonymity for fear of reprisal. There also have been a few high-profile defections from lower-ranked soldiers that have become social media sensations.
One is Giomar Flores, a low-ranking naval intelligence officer who in June released a video calling for the armed forces to uphold the constitution. Before fleeing to Colombia, where the video was recorded, he was assigned to policing food lines in Falcon state, a job that in theory afforded access to hard-to-find staples but which ended up turning him against the institution he loved.
“I decided my future was worth more than a bag of food,” the 25-year-old Flores said in an interview with The Associated Press from Bogota.
He said the top military command was corrupted by the government and divisions within the institution more apparent than ever.
“The armed forces today are like a snake, whose head is the top command that sadly is subordinated to the regime,” Flores said. “If you cut off the head, you’ll find us the troops.”
But a full-grown rebellion such as the one led by then-Lt. Col. Chavez in 1992 faces enormous obstacles, not the least of which is a dedicated counterespionage effort by Maduro.
“It’s very hard to create critical mass without being found out,” said Ivan Briscoe, head Latin American analyst for the International Crisis Group. “In an era of instant digital communications, authorities can be alerted to the risk of destabilization very quickly.”
Far from resolving Venezuela’s problems, a coup would trigger a full-blown international crisis and likely split the military, leading to even higher levels of violence approaching a civil war, Briscoe said. Opposition leaders, wary of awakening ghosts in a region that has turned its back on a century of military takeovers, are instead calling for behind-the-scenes pressure and restraint on using force against protesters.
A failure of the socialist system also could expose many senior officers to prosecution for human rights abuses and corruption. Several have already been targeted by U.S. sanctions, including the head of the army and national guard.
The opposition has gone to great lengths to say it will avoid a witch hunt if it gains power. But many in the military are unconvinced that any promises from the traditionally fragmented opposition can be taken seriously, given the huge challenges it would face governing, Garcia Plaza said.
“Many would rather trust the devil they know then the one they don’t,” he said.
___
Associated Press writer Jorge Rueda reported this story in Caracas and AP writer Joshua Goodman reported from Bogota, Colombia.
Copyright 2017 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
