Climate Challenge Week: Reconstructing the past with science

Answering common questions about climate change each day of Earth Week

Climate Challenge Day 1 -- Science: Reconstructing the past

Happy Earth Week!

Teaming up with NBC’s Climate Challenge week, Local 4 meteorologist Paul Gross will answer the most-asked questions about climate change all week long.

On Monday, we’re addressing the question of “how we know what we know” -- in other words, how do we know what global temperatures and atmospheric composition were hundreds, thousands and even millions of years ago.

We have standardized temperature records dating back to the mid to late 1800s, but when going back hundreds of years -- even one or two thousand years -- we use tree rings. Scientists also use coral rings to determine past ocean temperatures.

Ice cores drilled in the arctic allow scientists to study trapped pockets of ancient air, which tells us about both global temperatures and what our air was made up of millions of years ago.

Watch the full report in the video above.

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