Global heat, fires and floods: How much did climate change fuel that hellish July?

Doyle Rice | USA TODAY

Show Caption Hide Caption A record number of Americans now believe in global warming, poll says According to a new poll by University of Michigan's Center for Local, State, and Urban Policy, more Americans than ever now believe that global warming is occurring.

The fierce July that saw monstrous wildfires, record heat and unprecedented flooding across the globe was fueled by man-made climate change, scientists said – and these extremes are likely to become a fact of life.

"Overall, globally, what we’ve been seeing is exactly what has been predicted for decades," said Noah Diffenbaugh, a geoscientist at Stanford University. Climate change is "upping the odds that when these heat waves happen that they’re hotter and more severe."

Record-breaking heat waves and extreme rainfall are likely to become more common because the buildup of greenhouse gases – such as carbon dioxide from the burning of coal, oil and gas – is altering the atmosphere, according to the British journal Nature. Warmer air contains more water vapor and stores more energy; the increasing temperatures can also change large-scale atmospheric circulation patterns.

Deadly fires that have had California under siege the past few weeks are another example. Fires have also scorched Yosemite, Yellowstone, Crater Lake, Sequoia and Grand Canyon national parks, burning an area larger than 325 Manhattan Islands.

A summer of fire like this one has become more common in recent years: The number of large forest fires in the western USA and Alaska has increased since the early 1980s and is projected to further increase in those regions as the climate changes, according to a report from the U.S. Global Change Research Program.

In fact, the number of acres burned in the USA by wildfire has doubled compared with 30 years ago. Last year, more than 10 million acres burned. Over the past five years, an average of 6.7 million acres burned a year.

UCLA climate scientist Daniel Swain said about half of the increase can be blamed on the extreme warmth fueled by climate change. He said other factors include homes built in high-risk fire areas. "We've put a lot of people and a lot of stuff in harm's way," Swain said.

The USA has not been alone. Tinder-dry conditions and record heat triggered a firestorm in Greece last month, killing more than 90 people.

Heavy rain and floods in July were devastating: Hundreds of people were killed in Japan, India, Vietnam, Myanmar, Laos, the Philippines and Sudan.

July was one of the wettest months on record across the eastern USA as days of relentless rain put millions of people at risk of flash flooding.

This isn't a blip: Extreme one-day rainfall across the nation has increased 80 percent over the past 30 years. Ellicott City, Maryland, for example, has had so-called thousand-year floods in 2016 – and this year.

The heart of hurricane season is around the corner, and scientists issued a dire report about one of last year's worst disasters: Hurricane Harvey was supercharged by global warming as it dumped 15 percent more rain on Houston than it would have without it.

For many, it's the heat records that have been the most extraordinary: Northern Finland, above the Arctic Circle, hit 90 degrees; a possible all-time record for Africa of 124 degrees was measured in Algeria; the mercury hit 106 in Japan, an all-time mark during a heat wave that killed dozens; fierce heat in Canada killed at least 70 people in late June and early July.

Rivers in Germany have soaked up so much heat that fish are beginning to suffocate. Several of Germany’s nuclear power stations reduced energy output because rivers used to cool the power plants are too warm.

In the USA, there were 1,782 new daily high temperatures, 101 new monthly heat records and 29 all-time highs in July, many of which were recorded in Texas, New Mexico and Louisiana, according to the National Oceanic and Atmospheric Administration.

Notorious hot spot Death Valley, California, set a record in July for hottest month ever measured at a U.S. station with an average temperature of 108 degrees, the Weather Underground reported.

"It’s not rocket science," Penn State University climate scientist Michael Mann said. "You make the Earth hotter, you’re going to have more extreme heat. You’re going to have longer periods of extreme heat, you’re going to have more intense heat, and that’s what we’re seeing."

Heat waves are among the most clear-cut signs of climate change, according to a report in 2016 from the National Academy of Sciences.

More: A hellish July validates climate change forecasts

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A report last week from the University of Oxford in the United Kingdom said climate change more than doubled the likelihood of this year's European heat wave, which has reached summer temperatures that could eventually become the norm.

What to do? Reduce or stop burning fossil fuels, scientists said. “Limiting climate change to well below 2 degrees Celsius (3.6 degrees Fahrenheit) would considerably reduce the changes in heat waves," said Corinne Le Quéré of the University of East Anglia "Nevertheless, the changes observed so far will persist for centuries.”

Another expert, climate scientist Jennifer Francis of Rutgers University, said climate change is "costing people money, it’s costing people lives, it’s costing their own property, and climate change is affecting people today. It’s not a distant problem for their grandchildren."

A letter signed by more than 15,000 scientists last year said it best: "Soon it will be too late to shift course away from our failing trajectory, and time is running out. We must recognize, in our day-to-day lives and in our governing institutions, that Earth with all its life is our only home," the letter said.

Contributing: The Associated Press