Critical Time is in 2052 plus or minus 10 years

"A gloomy scenario is that humanity will enter a severe recession fed by the slow death of its host (the Earth)..."

Not the singularity I was hoping for (though they propose an ecological future as well)

Source paper at https://arxiv.org/pdf/cond-mat/0002075.pdf

The pdf is difficult to read on mobile and in any case a bit outside my expertise. Can somebody knowledgeable please write a TL;DR explaining the findimgs of this paper?