Will we be 'wiped out?' How climate change is affecting California
November 13, 2017 12:01 AM
California could one day be uninhabitable. Fire. Heat. Floods. Infestation. Disease. Suffering.
Scientists have for years warned about the ravaging consequences of a warming planet. Decamping for the 23rd session of the Conference of the Parties to the U.N. Convention on Climate Change, California academics and political leaders were mulling how to better deploy the distressing projections to give unwary citizens a better understanding of what's at stake and compel them to see the wisdom of embracing sustainability.
"This is bad stuff. It doesn't get any worse," Gov. Jerry Brown lamented to scientists, religious and political leaders in Europe ahead of the conference. "The threat is profound. It will alter human civilization. It's not decades away. It's closer than you think," the Democratic governor added later.
Rising temperatures reaching a tipping point would cause massive destruction, exacerbating inequality, poverty and migration patterns. The warnings are embedded in the speeches and calls to action by Americans at the conference in Germany. Brown, who has made climate change the central mission of his current stint as governor after serving before from 1975 to 1983, told European leaders that the recent fires in California, stoked by high winds and low humidity, were the latest sign of a planet in the throes of immense changes.
The state used to have a fire season of a few summer months, he said. "Now, we are fighting fires virtually the entire year."
"The science is getting clearer and the extreme weather events are getting more frequent. All of that leads to more understanding, more clarity and then more action," Brown said on a panel in Bonn. "The only question is will human beings be able to react in time, or will we have to get such an extreme event that we get wiped out?"
Assembled scientists said lessening public health impacts must be central to policies that stabilize the temperature change below dangerous levels.
"That message affects everyone everywhere," said Dr. Maria Neira, director of public health and the environment at the World Health Organization.
Our summers will feel like Tucson if we don't make changes.
Experts believe the health impacts of climate change will continue to be a focus across the Central Valley of California, where by the end of the century, annual summer temperature averages in the Sacramento region are projected to increase between nearly 4 degrees and 7 degrees Fahrenheit.
The area also is expected to experience an intense urban heat-island effect – which could make it seem 10 degrees hotter in urban areas than rural locales.
The number of extreme heat days, in which temperatures reach 101 degrees or more, is expected to increase from four days per year to 17 days by the middle of the century to 45 days by the end of the century, said Kathleen Ave, who heads up a local climate readiness collaborative. She believes that disseminating more information as it becomes available will give people a better sense of the various costs.
"Our summers will feel like Tucson if we don't make changes" like reducing greenhouse gas emissions, Ave said.
The six-county Capitol region already exceeds the state average in heat-related illnesses and deaths, according to the California Department of Public Health. For vulnerable populations – those with chronic diseases – the elevated heat levels put additional stress on the body.
Rising temperatures also affect air quality because chemical reactions that cause deterioration in air quality are temperature sensitive.
In Los Angeles, University of California scientists anticipate the number of days registering at 95 degrees or higher will increase to 22 by 2050, then to 54 by 2100. In the San Gabriel Valley, extreme heat days could go from 32 to 74 by 2050, and 117 by 2100.
Across the U.S., deaths from extreme heat and heat waves could double by 2050 in 21 cities.
California's climate of the future will still be Mediterranean: Rain in winter, heat in the summers. But the summers will be hotter, intensifying the summer drought and creating fuels more primed to burn.
Precipitation is coming more frequently as rain rather than snow, experts say. The snow that does fall is melting sooner, and will continue to shrink dramatically by the end of the century. This will have major implications for a state that relies on snowpack for water.
When the snow disappears, California will lose what for decades has acted as a natural storage system. Alex Hall, a UCLA professor whose research focuses on reducing uncertainties associated with climate change, said there is mounting evidence that the pattern of long droughts followed by big wet years will become more exaggerated.
"The past few years are a harbinger of what is to come," he said. "We had a blockbuster last year, by some measures the most precipitation in the historical record. And we had before that this very deep drought with unprecedented tree mortality."
The tree mortality crisis in the Southern Sierra is moving north; caused by warming and different invasive and noninvasive pine beetles.
As temperatures warm, there are fewer freeze days, which were nature's way of managing the beetle populations. Tree species that have developed to be drought-tolerant can shut down their photosynthesis process to manage the shortage and then open back up the next year when the drought has passed. But because the droughts have become longer, trees lack the necessary water, and die. Forests can also become a tinderbox for larger, hotter fires that sterilize the soil rather than the kinds of blazes that promote regeneration.
The fossil record indicates that species move when the climate undergoes dramatic changes. David Ackerly, a biologist at UC Berkeley, said a big challenge of 21st-century climate change is how rapidly the changes are taking place – faster than what scientists have ever seen.
"In broad strokes, we know that a lot of species can't move fast enough to keep up with projections, but what we know less about is what happens to them," Ackerly said. A warm spring can cause plants to leaf out early or flower early; then a late frost makes them more vulnerable.
Diversity is essential to the functioning of an ecosystem and can makes it more resilient in the face of adversities like drought. Ackerly contends there is something deeper at stake for the public.
"It's an ethical, aesthetic and even personal sense of loss that could be felt across society when we are no longer be able to hang onto a place," he said.
California is expected to see greater sea-level rise than the world average because of melting ice sheets.
In Mendocino, the rise is projected at between five and 24 inches by 2050, rising to between 17 and 66 inches by 2100. The melting ice in Antarctica will become a larger contributor to the rise than warming waters and melting mountain glaciers, one study found.
There are direct economic costs as well. UC Berkeley scientists released another study this summer that found the state's economy will lose billions of dollars a year to climate change. It concluded that warming will widen income gaps between rich and poor areas of the country because hotter places, where incomes are generally less, will suffer the worst consequences.
Brown believes it will take "big thinking" to reverse the climate impacts.
The warming temperatures are exposing the ways in which society is not planning sustainably, said Hall, the UCLA scientist.
Hall said adapting to the new reality could be more difficult for people in expansive California.
"We could just keep growing and keep developing and keep prospering," he said. "I certainly hope we can keep prospering, but I think we're going to have to think carefully about doing that in a sustainable way."