The average concentration of carbon dioxide in Earth’s atmosphere just topped 410 parts per million, according to measurements from Mauna Loa Observatory in Hawaii.
It’s the highest CO2 level in the 800,000 years for which we have good data. This is expected to have a catastrophic effect on human health and the planet itself.
We have a pretty good idea of what Earth’s atmosphere has looked like for the past 800,000 years.
Humans like us — Homo sapiens— evolved only about 200,000 years ago, but ice-core records reveal intricate details of our planet’s history from long before humans existed. By drilling more than 3 kilometers deep into the ice sheets over Greenland and Antarctica, scientists can see how temperature and atmospheric carbon-dioxide levels have changed since then.
From that record, we know the atmosphere and the air that we breathe has never had as much carbon dioxide in it as it does today.
For the first time in recorded history, the average monthly level of CO2 in the atmosphere exceeded 410 parts per million in April, according to observations at the Mauna Loa Observatory in Hawaii.
The record is not a coincidence — humans have rapidly transformed the air we breathe by pumping CO2 into it over the past two centuries. In recent years, we’ve pushed those gas levels into uncharted territory.
That change has inevitable and scary consequences. Research indicates that if unchecked, increased CO2 levels could lead to tens of thousands of pollution-related deaths, reach a point at which it slows human cognition, and contribute to rising sea levels, searing heat waves, and superstorms that scientists project as effects of climate change.
“As a scientist, what concerns me the most is what this continued rise actually means: that we are continuing full speed ahead with an unprecedented experiment with our planet, the only home we have,” Katharine Hayhoe, a climate scientist, said on Twitter.
For the 800,000 years for which we have records, average global CO2 levels fluctuated between about 170 ppm and 280 ppm. Once humans started to burn fossil fuels in the industrial era, things changed rapidly.
Only in the industrial era has the number risen above 300 ppm. The concentration first crept above 400 ppm in 2013, and it continues to climb.
There’s a debate among scientists about the last time CO2 levels were this high. It might have been during the Pliocene era, 2 million to 4.6 million years ago, when sea levels were 60 to 80 feet higher than today. Or it may have been in the Miocene, 10 million to 14 million years ago, when seas were more than 100 feet higher than now.
In our 800,000-year record, it took about 1,000 years for CO2 levels to increase by 35 ppm. We’re currently averaging an increase of more than 2 ppm a year, meaning we could hit an average of 500 ppm within the next 45 years.
Humans have never had to breathe air like this. And it does not seem to be good for us.
Read the full story at Business Insider
