The average global temperature is much higher and rising more rapidly than “anything modern civilization has experienced,” according to David Easterling, one of the authors of a new US government report that delivers a dire warning about our future.
Thousands more could die, food will be scarcer, and the US economy could lose hundreds of billions of dollars – or, in the worst-case scenario, more than 10% of its GDP – by the end of the century.
Released Friday, the Fourth National Climate Assessment was put together with the help of 1,000 people, including 300 leading scientists, roughly half from outside the government. It comes from the US Global Change Research Program, a team of 13 federal agencies, and is the second of two volumes. The first, released in November 2017, concluded that there is “no convincing alternative explanation” for the changing climate other than “human activities, especially emissions of greenhouse gases.”
The report breaks down the possible impact of climate change by US region and looks at the effects climate change will have on health, economy and infrastructure. Here are some of its key predictions:
1. Crop production will decline.
Farmers will face extremely tough times. The quality and quantity of crops will decline across the United States due to higher temperatures, drought and flooding.
In parts of the Midwest, farms will be able to produce only about 75% of the corn they produce today, and the southern part of the region could lose more than 25% of its soybeans.
By 2100, higher temperatures in places like Yolo County, California, could make it too hot to cultivate walnuts. Climate change could also severely limit almond production in California.
2. Cows could have it bad.
Heat stress, which cost the dairy industry $1.2 billion in 2010, will become an even bigger issue, potentially causing average dairy production to fall between 0.60% and 1.35% over the next 12 years.
Livestock for meat could struggle to find plants to graze on, and heat stress could impact their numbers.
3. Food sources from the sea will decline.
There won’t be as many oysters, shrimp or crab due to ocean acidification. The report predicts a $230 million loss for that industry by the end of the century. Annual oyster harvests in the Southeast will decline by 46% under the worst-case scenario by the end of the century.
Fish stocks overall may decline as red tides – algae bloom that deplete oxygen in the water and can kill sea life – become more common. It was a red tide that triggered a state of emergency in Florida in August.
The coral reefs that support diverse fish life off the Florida Keys are already declining and could be lost in the coming decades due to higher temperatures.
River fish could also die off; higher temperatures have already led to die-offs due to proliferative kidney disease.
Warmer temperatures were a problem for endangered sockeye salmon and Chinook in the Columbia River when they suffered a serious die-off in 2015.
4. Food- and waterborne illness will spread.
Weather that is bad for farmers is good for spreading food- and waterborne diseases, and more people will be exposed to them.
Marine toxins and pathogens will contaminate seafood. The waterborne bacteria Vibrio, which is already causing thousands of illnesses a year, will expand to seafood in northern seas and affect oysters grown in the Northeast.
Floods and heavy rains that can cause sewers to overflow can contaminate drinking water, leading to more stomach problems, studies have shown.
Droughts could cause more skin and eye infections, due to lack of water for personal hygiene. Other waterborne diseases that could spread include hepatitis A, salmonellosis, shigellosis, typhoid and E. coli.
5. Bugs will bug us more.
Weather that’s bad for crops is good for bugs.
Mosquitoes and ticks love warmer and wetter temperatures. That means diseases such as dengue, chikungunya and Zika will be more widespread. West Nile cases are expected to more than double by 2050 due to increasing temperatures.
The Northeast could see more cases of Lyme disease as the tick season expands in states like Maine and Pennsylvania.
6. It will be hard to breathe.
Asthma and allergies will also be worse due to climate change. The pollen season will intensify and lengthen in parts of the United States due to warmer temperatures.
Oak pollen in the Midwest will send more people to the emergency room for asthma, costing up to $170,000 annually, according to the report.
Urban areas with higher concentrations of CO2 will see more allergy-causing plants such as ragweed growing faster.
Increased rain in some areas will encourage mold growth indoors, which can make asthma symptoms worse.