By Tim Radford
Climate change means a big shift for city dwellers worldwide. Americans can look ahead to very different cities as the US climate heads south.
If the world continues to burn ever-increasing levels of fossil fuels, then life will change predictably for millions of American city dwellers as the US climate heats up. They will find conditions that will make it seem as if they have shifted south by as much as 850 kilometres.
New Yorkers will find themselves experiencing temperature and rainfall conditions appropriate to a small town in Arkansas. People from Los Angeles will discover what it is like to live, right now, on the southernmost tip of the Baja peninsula, Mexico. People in Abilene, Texas will find that it is as if they had crossed their own frontier, deep into Salinas, Mexico.
The lawmakers in Washington will have consigned themselves to conditions appropriate to Greenwood, Mississippi. Columbus, Ohio, will enjoy the climate of Jonesboro, Arkansas. Folk of Anchorage, Alaska, will find out what it feels like to live on Vancouver Sound. People of Vancouver, meanwhile, will feel as if they had crossed the border into Seattle, Washington.
This exercise in precision forecasting, published in the journal Nature Communications, has been tested in computer simulations for approximately 250 million US and Canadian citizens in 540 cities.
That is, around three quarters of all the population of the United States, and half of all Canadians, can now check the rainfall and temperature changes they can expect in one human lifetime, somewhere between 2070 and 2099.
There are a number of possible climate shifts, depending on whether or not 195 nations fulfil the vow made in Paris in 2015 to work to keep the average rise in global temperatures to “well below” 2°C by 2100.
In fact, President Trump has announced a US withdrawal from the Paris Agreement, and many of the nations that stand by the promise have yet to commit to convincing action.
So researchers continue to incorporate the notorious “business-as-usual” scenario in their simulations. So far, these have already predicted a sweltering future for many US cities, with devastating consequences for electrical power supplies and ever more destructive superstorms, megadroughts and floods, with huge economic costs for American government, business and taxpayers.
And, other researchers have found, climate change may already be at work: there is evidence that the division between the more arid American West and the more fertile eastern states has begun to shift significantly.
Long trip south
So the latest research could prove another way of bringing home to US citizens some of the challenges ahead.
“Under current high emissions, the average urban dweller is going to have to drive more than 500 miles (850 kms) to the south to find a climate like that expected in their home city by 2080. Not only is climate changing, but climates that don’t presently exist in North America will be prevalent in a lot of urban areas,” said Matt Fitzpatrick, of the University of Maryland, who led the study.
“Within the lifetime of children living today, the climate of many regions is projected to change from the familiar to conditions unlike those experienced in the same place by their parents, grandparents or perhaps any generation in millennia,” he said.
“It is my hope that people have that ‘wow’ moment, and it sinks in for the first time the scale of the changes we’re expecting in a single generation.”
This article was originally published on Climate News Network.Tim Radford, a founding editor of Climate News Network, worked for The Guardian for 32 years, for most of that time as science editor. He has been covering climate change since 1988.