So many like to point to industrial revolution for causing this.
That's because humans now emit more CO2 than volcanism.
Yet, what this study is really saying is that for centuries, if not millenniums, man had been overwhelming nature and slowly breaking down its ability to absorb the co2.
Yes, that is also true. We were deforesting the planet in pursuit of war. Most of the really heavy deforestation came when the big countries went naval warfare. We were cutting them down, making them into boats, then putting them out into the ocean and sinking them and losing that wood forever.
Of course, today we're still doing the equivalent; just try getting a permit to cut down a tree in Japan and use it for something, but they are buying California's redwoods as fast as they can be shipped over there. Then they are coating them in tar and sinking them under the ocean for storage. What are the odds that some cataclysm will remove them from the equation? Pretty goddamn good in Japan. We're cutting down the redwoods for nothing, as a species. Just to move some numbers around.
If there were such a thing as karma, humanity would deserve to die.