This much we know: seven of our 10 warmest years in the U.S. have occurred since 1998, and globally the 15 hottest years on record have all occurred since 1997. The American West has been steadily drying over recent decades, and last year wildfires burned 9.3 million acres of forests and fields.
We are already paying high costs for the consequences of our changing climate. Last year, crop losses due to record drought, damage from storms and floods, wildfires and other disasters aggravated by climate change caused $140 billion in damage in the U.S. alone. New York City says it will need to spend $20 billion to protect itself from rising sea levels caused by climate change and to fortify its defenses against a repeat of the devastating sea surge from Superstorm Sandy.