Climate change is back in the news with the President of the United States rolling out a big climate change assessment early last month and cable news like CNN covering the hot topic on shows likeCrossfire. But the big story that has been under told in the media is the record level of CO2 in the atmosphere, reaching over 400 parts per million (ppm) for the first time in recorded history, and much longer than that in actual history.
The last time CO2 reached today’s atmospheric levels was about 3.6 million years ago (before humans existed).
That’s according to a study published by UMass Amherst. Carbon dioxide ranged from 380 to 450 parts per million during this middle Pliocene period.
A few quick facts about the earth during Pliocene times from theUniversity of California San Diego:
- Humans didn’t exist.
- Global average temperatures were 3 to 4 degrees C warmer than today (5.4 to 7.2 degrees F).
- Polar temperatures were as much as 10 degrees C warmer than today (18 degrees F).
- The Arctic was ice-free.
- Sea level was between five and 40 meters higher (16 to 130 feet) than today.
- Coral reefs suffered mass die-offs.
As you may hear from time to time, the climate certainly does get warmer and cooler. There are cycles, no doubt. The question, then: is what we are experiencing now abnormal, and how abnormal is it?
Over the last 400,000 years or so, the Earth has gone through 4 major ice-age cycles, the last one ending about 12,000 years ago. Naturally, we are in a stage of warming. But when compared to the last four warm periods that coincide with the cooling periods, something is way off, and it should alarm anyone noticing it. Normally, carbon dioxide in the atmosphere would range between 180-280 ppm, at least during these last 4 cycles. The amount of CO2 in the atmosphere goes up and down with global temperature averages in syncopation. The 400 ppm of CO2 in the atmosphere represents an increase of 40% since the beginning of the Industrial Revolution. We know we’ve been burning mass amounts of carbon fuel during this time. We also know that this trend is only getting worse.
These facts are real. They have been verified and reverified by a variety of sources. The only thing scientists seemingly struggle with is predicting exactly what will happen year by year. They are much better at predicting general trends over longer periods of times. Some prediction models haven’t been right, and that has been ammo for opponents of climate change theory. But the basic facts remain and are undeniable. Carbon dioxide levels are as high as they’ve been in over 3 million years. Carbon dioxide levels coincide with temperature. When temperature catches up with carbon dioxide, the world is going to dramatically change. If CO2 emission trends continue, we are headed to much more than 400 ppm in as little as 100 years. The results could be considerably worse for the planet if things do not change.