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Climate Change Science Basics
This training is also part of the Core Volunteer Training series.
What's the actual science behind global warming?
The earth radiates some of its heat out to space naturally, but certain gases – ‘greenhouse gases’ – trap a portion of this heat radiation. Carbon dioxide, CO2, is an important greenhouse gas. Even at a very low concentration, CO2 has a powerful effect on the earth’s temperature. If there was no CO2 in the atmosphere, we would freeze, but just a little is enough to sustain life.
For about 10,000 years, the CO2 level was quite steady, giving us a stable climate in which to live and grow. But when we discovered all the things we could achieve with fossil fuels, we started burning them at an accelerating rate. Burning those fuels converts carbon that’s been buried for millions of years into CO2 that is steadily building up.
Scientists discovered the greenhouse effect in the 1850’s, [1,2] but it wasn’t until 1958 that we were able to measure CO2 in the atmosphere and measure how fast it increases. [3] As of May 2018, it had climbed from 280 to 410 parts per million (ppm). [4]
That amount of CO2 accounts for about half of the fossil carbon we’ve burned in modern times. [5] What happened to the rest of it? Most of it has gone into the ocean, causing the water to become more acidic, which is detrimental to important marine life. [6]
Human activity, mostly fossil fuel burning, currently adds over 1,000 tons of CO2 per secondto the atmosphere. [7]
Natural cycles? Volcanoes? The sun? These have all been ruled out. [8] They are either too small, too slow, or going in the opposite direction. It’s us.
The Scientific Consensus
There are only a very few, and even fewer who have scientific backgrounds relevant to climate science. Many individuals who pose as “experts” in media sources are not scientists at all, or else have no real background in climate science.
You want proof? Seven different research groups looked into this over the last 10 years, examining thousands of papers and/or asking hundreds of scientists directly for their position on climate change. They found that between 91 and 100 percent of published climate scientists agreed, based on the evidence, that human-caused global warming is occurring. The average was about 97 percent. [1] Not only that, but the National Academy of Sciences and their counterparts from 79 other nations also agree, as do all major American member organizations of physicists, chemists, meteorologists, and astronomers. Not a single one claims that human-influenced global warming is in doubt. Not one. [2]
This is important, because when people learn how strong the scientific agreement really is, they are more inclined to transcend political affiliations and support public policy solutions to climate change. [3]
Feel free to bring this message, which has been found to act as a gateway belief, to your community: 97 percent of climate scientists are convinced, based on the evidence, that human-caused global warming is happening.
See the following or scroll to watch the Climate Change Science Basics video below:
The Carbon Cycle
(4:11)
How Humans Factor In
(11:28)
The Scientific Consensus
(18:33)
Responding To Common Questions
(21:31)
A Success Story
(30:24)
Final Takeaways on Communicating
(36:18)
Connect With Local Climate Scientists
(40:26)
Download PowerPoint or Google Slides presentation.
Download the video.To skip ahead to a specific section go to the time indicated in parenthesis.
The Carbon Cycle
(4:11)
How Humans Factor In
(11:28)
The Scientific Consensus
(18:33)
Responding To Common Questions
(21:31)
A Success Story
(30:24)
Final Takeaways on Communicating
(36:18)
Connect With Local Climate Scientists
(40:26)
- Download this episode (right click and save).
- Find the episode on CCL’s iTunes channel.
Dr. Kirtland Turner's short resource list to begin your own research and climate science communications preparation:
4. Real Climate Blog (Gavin Schmidt)