"They’ve tried to correlate too much change to CO2 content and not enough to changed land use."
or any other possible explanation for atmospheric cycles/regulation for that matter.
Anybody applying for research grants to study alternative sources/reasons for climate variations other than CO2 never get funded. Even long established theories based on solar-activity cycles or geothermal dynamics have been dismissed as insignificant - it has to be all about fossil fuels and CO2 or you will never get funding from the government and you will never get published in "scientific" journals.
science has become as politicized was our judicial system - reality is for sale...