An interesting new study abut the history of Arctic ice presence and changes. The main finding is that there is evidence for ice formation on Greenland and over the Arctic Ocean a bit more than 45 million years ago, which was during the warm Eocene period, much earlier than generally recognized, and that since then it has advanced and retreated a number of times. The full study is available with open access. I would like to mention that the data used for historical CO2 readings, which was not developed by these authors, would be disputed by many scientists who are now thinking the numbers were considerably lower than these in ancient times (see following story). Thus the conclusion about where to place the tipping point could also be revised, probably well below 500.
–Link to the full study: https://www.nature.com/articles/s41467-018-03180-5#Sec8
Here is a prominent example of a recent study by a research group that has investigated new ideas about how best to determine CO2 numbers in ancient times, and is ready to accept the possibility that a considerable lowering of earlier estimates has merit. This is a subject that has much interest among those who want to know exactly what things were like in the past with CO2 around 450 or so, which is likely to be repeated in about twenty years.
Deforestation of the Congo Basin is facing an acceleration (Mongabay). Thousands of square miles have been licensed for clearance for rubber and palm oil plantations. This is an area that is relatively undeveloped in comparison with other parts of the world having similar features. “All the ingredients are in place for a repeat of the disaster wrought by industrial agriculture to rainforests elsewhere….There is still a chance to prevent this, but time is running out.”
Also from Mongabay, a vast savannah in Brazil known as the Cerrado is steadily being converted to soy fields and cow pastures. The region is recognized as a crucial part of Brazilian watershed and for its powerful ability to store carbon, both of which are weakening, while victimizing wildlife habitat.
A detailed study of the potential for BECCS to collect and store carbon in the US. This is today’s leading methodology for achieving “negative emissions” that would probably work, and have a somewhat reasonable cost. The US is considered an attractive location because it has relatively high biomass productivity and plenty of known storage sites for sequestering the CO2. One sentence that caught my eye—“If all of the biomass available in 2020 were used for BECCS, it could, in theory, provide 370-400MtCO2 per year.” I believe that number is a little less than 1% of the current rate of global emissions.