Climate change 'has moved firmly into the present,' U.S. report says

Global warming is rapidly turning America into a stormy and dangerous place, with rising seas and disasters costing citizens from flood-stricken Florida to the wildfire-ravaged West, according to a new U.S. federal scientific report.

Climate change's assorted harms "are expected to become increasingly disruptive across the nation throughout this century and beyond," the National Climate Assessment concluded Tuesday.

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The report emphasizes how warming and its all-too-wild weather are changing daily lives, even using the phrase "climate disruption" as another way of saying global warming.

Still, it's not too late to prevent the worst of climate change, says the 840-page report, which the White House is highlighting as it tries to jump-start often stalled efforts to curb heat-trapping gases.

We're being hit hard. We're holding steady, and we're getting hit in the jaw. We're starting to recover from one punch, and another punch comes.-Katharine Hayhoe, Texas Tech University climate researcher

However, if the U.S. and the world don't change the way they use energy, "we're still on the pathway to more damage and danger of the type that are described in great detail in the rest of this report," said study co-author Henry Jacoby, co-director of the Joint Program on the Science and Policy of Global Change at the Massachusetts Institute of Technology.

Jacoby, other scientists and White House officials said this is the most detailed and U.S.-focused scientific report on global warming.

"Climate change, once considered an issue for a distant future, has moved firmly into the present," the report says.

"Corn producers in Iowa, oyster growers in Washington state and maple syrup producers in Vermont are all observing climate-related changes that are outside of recent experience."

More severe storms, higher temperatures

The report looks at regional and state-level effects of global warming, compared with recent reports from the UN that lumped all of North America together.

"One of the things this report is tries to do is...try to explain to the person on the street that this is happening now and it’s going to get worse," Jacoby said in an interview with CBC's The Lang & O'Leary Exchange.

He points to a range of impacts of global warming that people see everyday, from the change in the growing season, to extreme heat, severe Atlantic storms and drought in some areas. These changes are far more than just variable weather, he said.

"If you look at what’s happening to the Arctic ice at your northern border, you are seeing changes to the ice like you haven’t seen in hundreds of years. We’re seeing change on a scale that’s going beyond variability," Jacoby said.

A draft of the report was released in January 2013, but this version has been reviewed by more scientists, the National Academy of Science and 13 government agencies and had public comment.

It is written in a bit more simple language so people could realize "that there's a new source of risk in their lives," said study lead author Gary Yohe of Wesleyan University in Connecticut.

Corn producers in Iowa, oyster growers in Washington state and maple syrup producers in Vermont are all observing climate-related changes that are outside of recent experience.-U.S. draft 2014 climate assessment report

Even though the nation's average temperature has risen by as much as 1.9 degrees since record keeping began in 1895, it's in the big, wild weather where the average person feels climate change the most, said co-author Katharine Hayhoe, a Texas Tech University climate scientist.

Extreme weather like droughts, storms and heat waves hit us in the pocketbooks and can be seen by our own eyes, she said.

And it's happening a lot more often lately.

The report says the intensity, frequency and duration of the strongest Atlantic hurricanes have increased since the early 1980s, but it is still uncertain how much of that is from man-made warming.

Winter storms have increased in frequency and intensity and shifted northward since the 1950s, it says. Also, heavy downpours are increasing — by 71 per cent in the northeast.

Heat waves, such as those in Texas in 2011 and the Midwest in 2012, are projected to intensify nationwide. Droughts in the southwest are expected to get stronger. Sea level has risen 20 centimetres since 1880 and is projected to rise between 0.3 meters and 1.2 metres by 2100.

Record-setting decade

Since January 2010, 43 of the lower 48 states have set at least one monthly record for heat, such as California having its warmest January on record this year. In the past 51 months, states have set 80 monthly records for heat, 33 records for being too wet, 12 for lack of rain and just three for cold, according to an Associated Press analysis of federal weather records.

"We're being hit hard," Hayhoe said, comparing America to a boxer. "We're holding steady, and we're getting hit in the jaw. We're starting to recover from one punch, and another punch comes."

The report also says "climate change threatens human health and well-being in many ways."

Those include smoke-filled air from more wildfires, smoggy air from pollution, more diseases from tainted food, water, mosquitoes and ticks.

And then there's more pollen because of warming weather and the effects of carbon dioxide on plants. Ragweed pollen season has lengthened by 24 days in the Minnesota-North Dakota region between 1995 and 2011, the report says. In other parts of the Midwest, the pollen season has gotten longer by anywhere from 11 days to 20 days.

And all this will come with a hefty cost, the report says.

Flooding alone may cost $325 billion by the year 2100 in one of the worst-case scenarios, with $130 billion of that in Florida, the report says. Already the droughts and heat waves of 2011 and 2012 added about $10 billion to farm costs, the report says.

Billion-dollar weather disasters have hit everywhere across the nation, but have hit Texas, Oklahoma and the southeast most often, the report says.