To limit global warming in 2100 to below 1.5C above pre-industrial levels, many scientists assume that the large-scale use of negative emissions in the latter half of the 21st century will be needed. Negative emissions “suck” CO2 out of the atmosphere, allowing a more gradual reduction of emissions in the near-term. Integrated assessment models (IAMs) that generate energy and emission pathways to limit warming to 1.5C have generally relied on large amounts of bioenergy with carbon capture and storage (BECCS) to provide the required negative emissions. Many deploy BECCS on a massive scale, allocating a land area up to five times the size of India to growing the biomass needed by 2100. Criticism of model reliance on BECCS has led researchers to examine the potential of “natural climate solutions” (NCS) to remove CO2 in the atmosphere through reforestation, land-use change and other ecosystem-based approaches. Here, Carbon Brief uses the recently published review of NCS to examine how big a role they could play in contributing to negative emissions. This analysis shows that NCS could provide a sizable portion of the required emissions and reduce the need for BECCS in pathways limiting warming to below 1.5C, particularly when coupled with faster emissions reductions over the next few decades.
Carbon Brief 21st May 2018 read more »
With world temperature rise already 1°C above pre-industrial levels, new research shows that there is only a 0.5°C safety margin left in the system before the most vulnerable groups of people suffer severely. The current political target, agreed in Paris more than two years ago, of aiming to prevent temperature from rising more than 1.5°C above pre-industrial levels, and certainly stopping a rise beyond 2°C, disguises the fact that we are already more than halfway to the danger point. And scientists have now shown that there is a huge difference in the consequences to the human race if the 1.5°C limit is exceeded and temperatures allowed to reach 2°C.
Climate News Network 22nd May 2018 read more »