The Register's editorial

A new federal report about climate change should be a wake-up call to Iowa, a state with an economy heavily dependent on agriculture.

It should also be a wake-up call to the 90 percent of registered Republicans here who see truth-telling as an essential trait in an American president, according to a new Des Moines Register/CNN/Mediacom Iowa Poll.

There are truths revealed by science. This country needs a president who believes them.

Which brings us to this report, compiled by 13 federal agencies. It concludes that without major change, the effects of global warming, including extreme heat and heavy downpours, will pose increasing challenges to “the quality and quantity of U.S. crop yields, livestock health, price stability and rural livelihoods.”

Corn and soybeans may not pollinate. The planting season could get even shorter. Soil erosion will be exacerbated. Nutrient runoff and algal blooms will further contaminate Iowa’s waterways. New diseases could be spread by insects and pests. The availability of food and water could be compromised.

The grim forecast is part of the Fourth National Climate Assessment, a study mandated by Congress and completed every four years.

What was President Trump’s response to his own administration’s report? He said he did not believe climate change is a pressing worry.

“One of the problems that a lot of people like myself, we have very high levels of intelligence but we’re not necessarily such believers,” Trump said during an interview with the Washington Post following release of the report.

More than 300 experts who certainly have very high levels of intelligence helped compile the 1,656-page assessment outlining the devastating effects of a changing climate on our economy, health and environment.

Despite the president’s subsequent rambling about trash, “very small” oceans and “record clean” air and water, the real experts on this issue say agricultural yields could fall to 1980s levels if action is not taken.

Iowa farmers are already trying to adapt to a changing climate. Researchers are testing how farmers can capture run-off and store it for later irrigation. Improved seed genetics enable plants to better withstand drought and disease.

But the report warns that technology is unlikely to be enough to stop the damage. We also need a concerted effort to reduce emissions of carbon dioxide from burning fossil fuels.

“With substantial and sustained reductions in greenhouse gas emissions, the increase in global annual average temperature relative to preindustrial times could be limited to less than 3.6°F,” according to the report. “Without significant greenhouse gas mitigation, the increase in global annual average temperature could reach 9°F or more by the end of this century.”

Translation: Humans can help slow climate change.

Those humans need to include the president of the United States, who is in a position to set policies and the tone of public discourse on this issue.

Unfortunately, Trump is moving the country — and the world — in the wrong direction by rolling back environmental regulations, embracing the coal industry, dismissing global climate agreements and disregarding science.

That puts the entire U.S. economy, and particularly Iowa’s economy, at risk.