In a letter from 255 members of the National Academy of Scientists, published in Science Magazine, they claim that climate change is a fact, as is the contribution of human activity to global warming. In a sharply worded letter decrying “McCarthy-like threats” the letter states in part:
“But there is nothing remotely identified in the recent events that changes the fundamental conclusions about climate change:
(i) The planet is warming due to increased concentrations of heat-trapping gases in our atmosphere. A snowy winter in Washington does not alter this fact.
(ii) Most of the increase in the concentration of these gases over the last century is due to human activities, especially the burning of fossil fuels and deforestation.
(iii) Natural causes always play a role in changing Earth’s climate, but are now being overwhelmed by human-induced changes.
(iv) Warming the planet will cause many other climatic patterns to change at speeds unprecedented in modern times, including increasing rates of sea-level rise and alterations in the hydrologic cycle. Rising concentrations of carbon dioxide are making the oceans more acidic.
(v) The combination of these complex climate changes threatens coastal communities and cities, our food and water supplies, marine and freshwater ecosystems, forests, high mountain environments, and far more.”