World has a decade to bring climate change under control, say U.N.’s top scientists

Humanity has not moved fast enough to cut carbon emissions and must now make unprecedented changes in energy, transportation and other systems during the next decade to hold global warming to moderate levels.

Failure to act, according to a new report released by the top scientific panel studying climate change, will usher in rising temperatures, rising sea levels and severe weather changes affecting millions of people across the world.

The United Nations’ Intergovernmental Panel on Climate Change found that the globe could warm to 1.5 Celsius above preindustrial levels within 15 years. And to avoid more serious warming and its various consequences, the global community will need to cut carbon emissions in half by 2030 and be carbon-neutral by 2050.

“I thought that it was super-sobering,” said Amy Snover, director of the University of Washington’s Climate Impacts Group. “It’s super-frightening and serious, and it really emphasizes what in general I think we have all been thinking for quite some time, which is that this is a really serious deal.”

Snover, whose research and work focuses primarily on climate change adaptation in Washington, said the U.N. report helps “to put really specific outcomes on the choices we’re making right now as a society as far as how much climate change we’re willing to tolerate.”

The world temperature is now 1 degree Celsius above preindustrial levels. If global emissions don’t fall drastically, the world will reach the 1.5 degree mark sometime between 2030 and 2052. The report’s findings were announced Sunday in South Korea.

The U.N.’s scientific panel published the report after 91 scientists, from 40 countries, analyzed more than 6,000 scientific studies.

The science itself isn’t new. Instead, the report synthesized previously published and peer-reviewed climate change studies.

The report finds that with a 1.5 degree rise in temperature, between 70 and 90 percent of the world’s tropical coral reefs are expected to vanish. At 2 degrees, that number grows to more than 99 percent.

Additionally, at 1.5 degrees of warming, global sea levels are expected to rise .22 to .77 meters (less than a foot to 2.52 feet) by 2100. If the globe warms to 2 degrees Celsius above preindustrial levels, the seas will rise an additional .1 meter which, according to the report, would put an additional 10 million people at risk.

However, holding warming to 1.5 degrees could save an Alaska-size area of the Arctic from permafrost thaw, muting a feedback loop that could lead to still more global emissions. The occurrence of entirely ice-free summers in the Arctic Ocean goes from one per century to one per decade between 1.5 and 2 degrees, it found – one of many ways in which the mere half a degree has large real-world consequences, the Washington Post reported.

In short, the more emissions, the greater the impacts and the greater the heat. Risks of extreme heat and weather events rise as temperatures do, meaning these would be worse across the globe the more it warms.

That’s true in the Pacific Northwest, with some caveats.

Climate models that John Abatzoglou, a climate scientist at the University of Idaho, has run show a “substantial amount of warming” in the Northwest. If nothing is done to mitigate climate change and reduce emissions, temperatures could increase by 10 degrees Fahrenheit by the end of the century.

That’s the high end of the spectrum.

On the lower end, if global emissions fell enough to limit the global temperature increase to 1.5 degrees, Abatzoglou said the Northwest would likely still see increases of 2.5 degrees Celsius.

Those changes will primarily impact the the area’s water supplies.

“That moves your snow levels up by a few thousand feet,” he said. “When we look at some of the projections for snowpack, they don’t look great for our area because we have relatively low mountains.”

Abatzoglou studies the link between human-caused climate change and wildfires.

A reduction or loss of winter snowpack can mean warmer rivers, larger forest fires, and the loss or reduction of some recreational opportunity, like skiing.

Previous climate change models for Washington predict “extended periods” where the weekly average water temperature in many rivers and streams exceeds 69.8 degrees, according to a 2009 publication examining ways state wildlife managers and advocates can address a changing climate.

Overall, it has been predicted that the Columbia River’s water temperature will increase by one-tenth of a degree per year.

This summer stretches of the Yakima River reached 80 degrees – a temperature deadly to most fish.

Wildfires have become more intense, more frequent and larger in the past decades. August, traditionally prime recreation time in the Spokane area, has been choked with smoke.

“When you start peeling it back, climate is an underlying feature in almost every aspect of our life or our civilization,” Snover said. “If you look … you can find the threads that climate change is going to pull.”

According to the U.N. report, to reach the 1.5 degree threshold, the world’s percentage of electricity from renewables like solar and wind would have to jump from the current 24 percent to 50 or 60 percent within 10 years. Coal and gas plants that remain in operation would need to be equipped with technologies, collectively called carbon capture and storage, that prevent them from emitting carbon dioxide into the air and instead funnel it to be buried underground. By 2050, most coal plants would have to be shut down, according to the Washington Post.

Cars and other forms of transportation, meanwhile, would need to be electrified.

In order to keep global temperatures increases below 1.5 degrees, the IPCC reports global carbon dioxide emissions would need to fall precipitously by 2030.

That would necessitate huge changes. Trying to limit global warming to 1.5 degrees is a great goal, Abatzoglou said. Any effort in that direction will help. But he thinks it’s unlikely.

“I have skepticism over whether we can feasibly limit the amount of warming to 1.5 degrees Celsius,” he said.

Because the issue is global in scope, source and impact, it can be hard for individuals to feel that they can do anything, Snover said.

“People get overwhelmed and say, ‘Nothing I do matters.’ I turn it around and say the only thing that matters is what you do,” she said. “Local governments and state governments are on the front lines of dealing with those impacts and our goal is to develop science that is useful for helping them prepare.”

For instance, in August, the Spokane City Council passed legislation that would make the city receive all its electricity from renewable sources by 2030.

Also locally is the Climate Impacts Research Consortium’s Spokane Community Adaptation Project. Through the project a number of Spokane citizens are working with Abatzoglou and other researchers to “help prepare Spokane be more climate resilient.’

Still, Snover recognizes the challenge of engaging individuals in a complex and global issue.

“Frankly, it’s really hard,” she said. “It’s really hard to be working in an area where the consequences of these changes are really negative and we’re not acting with the urgency that we need to be. I am the kind of person that wants to make a difference and so I need to be working on it in some way. I can’t ignore it.”

The Washington Post contributed to this report.