Dr. Ryan Green just had a second manuscript accepted for publication, where we argue that the large-scale release of geologic carbon at the end of the last ice age is likely responsible for radiocarbon (14C) anomalies discovered in the Gulf of California region. Unlike any previous work, we argue that the carbon was released with and neutralized by alkalinity so as not to cause ocean acidification or atmospheric CO2 increase.
A new study led by Simone Moretti (MPIC) suggest there could be a general mechanism speeding up deep ocean circulation and raising atmospheric CO2, thereby producing a positive feedback. This mechanism is thought to help explain ice ages, but the new study now provides evidence it might have also amplified the warmest conditions of the Eocene hot-house climate.
In a new chapter for the third edition of the Treatise on Geochemistry with Kat Allen and Sandy Kirtland Turner, we systematically analyze the dynamics that couple climate and carbon cycle through CO2 radiative forcing. This includes the first analytical derivation of the silicate weathering timescale. The relevant context of proxy systems for climate and carbon cycle and terminology for coupled climate-carbon cycle change is intended to introduce Earth System science.
In a perspective on Quaternary climate change with Tom Chalk, published in the Encylopedia of Quaternary Science, we question the conventional wisdom that ice ages result from regular changes in Earth’s orbit or some other purely physical mechanism. We argue instead that the global carbon cycle and greenhouse gasses need to be included as a cause of climate change.
In a new synthesis review with Danny Sigman, published in the Oxford Research Encyclopedia of Climate Science, we entertain the possibility that changes in the ocean’s biological pump and alkalinity were the dominant driver of CO2 and global climate change during Pleistocene ice ages. We show that land-carbon changes effects were canceled by ocean carbonate compensation, and that ice sheet and temperature changes cancel each other. The effect of deep ocean carbon storage, in contrast, is amplified by carbonate compensation, yielding durable CO2 changes.
Ryan Green led a study investigating a the natural occurrence of geologic carbon release that is neutralized by alkalinity, so that it did not cause ocean acidification or atmospheric CO2 rise. The scale of the carbon pulse may have been twice the amount of all anthropogenic fossil fuel use combined. Studying this anomaly can give us clues about the effectiveness and environmental effects of purposeful Ocean Alkalinity Enhancement in an effort to neutralize anthropogenic CO2 and slow climate change.