At the same time, the groups warned that the national report should be viewed as a wakeup call for Americans to take climate change seriously, and to launch significant efforts to reduce greenhouse gas emissions in order to hedge against possible negative impacts and surprises. Places that Americans love, such as Florida's coral reefs and the alpine meadows of the Rocky Mountains, could suffer greatly from global warming, according to the report. The National Assessment shows that now more than ever the US must act to protect its national treasures. The report reveals that natural ecosystems are the most vulnerable to the harmful effects of climate change because they have very limited options to adapt to those changes and because they are already stressed through air and water pollution, habitat fragmentation, and overuse. It is also very likely that more rain will come in heavy downpours, increasing the risk of floods.
Ecosystems are highly vulnerable to the projected rate and magnitude of climate change.
The goods and services lost through the disappearance or fragmentation of certain ecosystems are likely to be costly or impossible to replace. Climate change and the resulting rise in sea level are likely to worsen threats to buildings, roads, powerlines and other infrastructure along the coast. Sea-level rise is very likely to cause the loss of some barrier beaches, islands, and wetlands, and worsen storm surges and flooding during storms. Overall, US crop productivity is likely to increase over the next few decades, but the gains will not be uniform across the nation. Falling prices and competition are likely to stress some farmers.