Search results
Results from the WOW.Com Content Network
The 2019 IPCC Special Report on the Ocean and Cryosphere in a Changing Climate defines a tipping point as: "A level of change in system properties beyond which a system reorganises, often in a non-linear manner, and does not return to the initial state even if the drivers of the change are abated. For the climate system, the term refers to a ...
From ancient times, people suspected that the climate of a region could change over the course of centuries. For example, Theophrastus, a pupil of Ancient Greek philosopher Aristotle in the 4th century BC, told how the draining of marshes had made a particular locality more susceptible to freezing, and speculated that lands became warmer when the clearing of forests exposed them to sunlight.
These historical impacts of climate change can improve human life and cause societies to flourish, or can be instrumental in civilization's societal collapse. The study seeks to define periods in human history where temperature or precipitation varied from what is observed in the present day.
The time from roughly 15,000 to 5,000 BCE was a time of transition, and swift and extensive environmental change, as the planet was moving from an Ice age, towards an interstadial (warm period). Sea levels rose dramatically (and are continuing to do so ), land that was depressed by glaciers began lifting up again , forests and deserts expanded ...
According to science historian Spencer R. Weart, Hansen's testimony increased public awareness of climate change. [81] According to Richard Besel of California Polytechnic State University, Hansen's testimony "was an important turning point in the history of global climate change."
500 million years of climate change Ice core data for the past 400,000 years, with the present at right. Note length of glacial cycles averages ~100,000 years. Blue curve is temperature, green curve is CO 2, and red curve is windblown glacial dust (loess).
World leaders are meeting in Paris this month in what amounts to a last-ditch effort to avert the worst ravages of climate change. Climatologists now say that the best case scenario — assuming immediate and dramatic emissions curbs — is that planetary surface temperatures will increase by at least 2 degrees Celsius in the coming decades.
Climate change adaptation has tended to be more of a focus for local authorities, while national and international politics has tended to focus on mitigation. There have been exceptions – in countries that feel especially exposed to the effects of climate change, sometimes the focus has been more on adaptation even at national level. [37]