2.13c: discuss the difference between anthropogenic and natural climate change over hundreds of thousands of years

Anthropogenic effects: changes brought about by human activities, such as burning fossil fuels, deforestation, and intensive agriculture

• human activity has overcome the influence of natural climate change over the last few hundred years
• the most potent greenhouse gases (CO2,NOx,CH4) are currently at their highest levels for over 650,000 years due to human activity

Natural climate change: changes brought about by orbital cycles (tilt, shape of orbit, precession) and greenhouse gases

• natural climate cycles have been occurring for millions of years

Evidence for anthropogenic climate change:

• long-term data shows that the climate has been naturally fluctuating between glacial and interglacial periods
• if climate change is natural, this pattern should continue
• short-term data shows that global temperatures have been rising since the beginning of the industrial period
• human activity is having more of an effect on climate change