![image](https://cdn.britannica.com/300x300/15/106515-004-540A3E17.jpg)
How did global warming start?
Scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect" — warming that results when the atmosphere traps heat radiating from Earth toward space.
When did climate change and global warming start?
Global warming is the long-term heating of Earth's surface observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere.
When was the last time the Earth was this hot?
Even after those first scorching millennia, however, the planet has often been much warmer than it is now. One of the warmest times was during the geologic period known as the Neoproterozoic, between 600 and 800 million years ago. Conditions were also frequently sweltering between 500 million and 250 million years ago.
What came first climate change or global warming?
The term "global warming," which describes an increase in the Earth's average temperature surface due to greenhouse gas emissions, is widely believed to have been coined in 1975 by Columbia University geochemist Wallace Broecker, according to NASA.