Scientists believe the Earth is rapidly approaching a catastrophic tipping point, driven by the activity of human beings, the Huffington Post reported this week.
The scientists argue that the Earth's climate is reaching a point of no return and that we are headed for rapid, destructive changes, the San Francisco Chronicle reported. The scientists say the changes will lead to mass extinctions, scarce resources for humans and eventual politcal and economic clashes.
The U.S. Environmental Protection Agency notes that Earth's average temperature has risen by 1.4 degrees in the last 100 years and could rise 2 to 11.5 degrees in the next 100 years.
The Nature Conservancy states that a quarter of the planet's species could go extinct by 2050. NASA predicts a decrease in crop yields for North America of 5 to 20 percent and up to 50 percent in Africa.
Scientists argue that one of the causes of climate change is the increase of carbon dioxide in the atmosphere. Since the Industrial Revolution began, scientist have said that human activity – deforestation, land use and the burning of fossil fuels – have increased carbon dioxide concentrations in the atmosphere by a third.
Critics of global warming say that the concern is overblown and off-base. Richard Lindzen, professor of meteorology at MIT, wrote in the Wall Street Journal that "Claims that climate change is accelerating are bizarre."
Lindzen stated that the Earth went thorugh a cooling period from the 15th century through the 19th century known at the Little Ice Age and some warming would be expected after that period.
U.S. Senator James Inhofe, R-OK, has been an outspoken critic of global warming science and suggested political motivations are behind it. Inhofe's book "Greatest Hoax: How the Global Warming Conspiracy Threatens Your Future" was published this year.