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Credit: BrAt82/Shutterstock.com.
Humans have caused major climate changes to happen already, and we have set in motion more changes still. However, if we stopped emitting greenhouse gases today, the rise in global temperatures would begin to flatten within a few years. Temperatures would then plateau but remain well-elevated for many, many centuries. There is a time lag between what we do and when we feel it, but that lag is less than a decade.

While the effects of human activities on Earth's climate to date are irreversible on the timescale of human lifetimes, every little bit of avoided future temperature increases results in less warming that would otherwise persist for essentially forever. The benefits of reduced greenhouse gas emissions occur on the same timescale as the political decisions that lead to those reductions.

Without major action to reduce emissions, global temperature is on track to rise by 2.5 °C to 4.5 °C (4.5 °F to 8 °F) by 2100, according to the latest estimates.

Thwaites Glacier
Thwaites Glacier. Credit: NASA.
But it may not be too late to avoid or limit some of the worst effects of climate change. Responding to climate change will involve a two-tier approach:

  • “Mitigation” – reducing the flow of greenhouse gases into the atmosphere
  • “Adaptation” – learning to live with, and adapt to, the climate change that has already been set in motion. The key question is, what will our emissions of carbon dioxide and other pollutants be in the years to come?

Read more about NASA's efforts to address climate change at https://climate.nasa.gov/solutions/resources/.

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