The Earth is dealing with something that it hasn’t faced in at least the last 800,000 years. It’s a dramatic shift in the levels of carbon dioxide present in the planet’s atmosphere, and it’s abundantly clear that mankind is the reason for the change.
If you’ve even casually kept an eye on environmental news over the past, say, three decades or so you already had a pretty good idea that this was happening, but the most recent data from the Scripps Institution of Oceanography makes it clear that the situation is truly unprecedented.
Scripps tracks the daily atmospheric CO2 levels of Earth, using data from the Mauna Loa Observatory in Hawaii to produce a graph that is known as the Keeling Curve. Named for scientist Charles Keeling, the graph tracks the changes in CO2 levels on a huge timescale, helping researchers to identify and differentiate short-lived trends from serious CO2 spikes.
Put simply, mankind has never see anything like this before. Here’s the portion of the graph showing changes in CO2 levels over the past 10,000 years:
Data from before realtime human observation was gleaned from ice core samples that show global CO2 levels dating back hundreds of thousands of years. As you can see in the graph, that massive spike is firmly linked to human habitation of the Earth.
Going back even farther, here’s a look at the CO2 levels of the past 800,000 years:
It’s clear that Earth has endured some significant changes to its CO2 levels in the past, occasionally even doubling for long stretches of time before calming down again. Still, there’s absolutely nothing in the ice record that comes close to matching the CO2 levels of today.
“The rise in CO2 is unambiguously caused by human activity, principally fossil-fuel burning,” Rob Monroe of Scripps recent wrote. “This is clear from the numbers: We know how much fossil fuel is converted into CO2 each year and emitted into the atmosphere. The CO2 doesn’t all stay there because some enters the ocean and some is taken up by photosynthesis, which ends up in land plants and various types of biomatter.”