New USGS Report Calculates Alaska’s Greenhouse Gas Potential
The scientists found that Alaska’s ecosystems currently capture as much carbon as they lose to the atmosphere. However, they said, rising temperatures, more wildfires and thawing permafrost still could tip the balance and make Alaska a net carbon source. That would further increase the concentration of gases that trap the sun’s energy and warm the Earth’s atmosphere.
Increases in wildfires are not accounted for in the CMIP5 models - the UK department of Energy and Climate Change (DECC) has confirmed.
the models used vary in what they include, and some feedbacks are absent as the understanding and modelling of these is not yet advanced enough to include. From those you raise, this applies to melting permafrost emissions, forest fires and wetlands decomposition.
DECC avoid saying how this affects the remaining carbon budget
DECC doesn’t estimate the remaining global carbon budget, however others such as the Global Carbon Project have estimated updates to the IPCC’s budget, based on emissions since 2010.
Anyone know how much the budgets should be decreased?
My rather rough calculations of the remaining budgets per person in the world - without reduction for missing feedbacks give
The remaining carbon budget for a 66% chance of avoiding 1.5˚C becomes
21 tonnes CO2 per person: 4 years to 1.5˚C
The remaining carbon budget for a 66% chance of avoiding 2.0˚C becomes…
85 tonnes CO2 per person: 16 years to 2.0˚C
These are for world average per person emissions. The populations of rich countries average much higher emissions.
P.S. I must admit some confusion between CO2 and CO2e in the calculations.
First, per the first & seconded attached plots (based on Jan-March, and Jan-April, respectively) and issued recently by Gavin Schmidt there is a real chance that we could exceed 1.5C by the end of 2016.
Second, the USGS report that you cited not only understates the possible implications of wildfires, it clearly understates the implications of methane emissions from Alaskan lakes as indicated by the following extract from:
Edited by Zhiliang Zhu and A. David McGuire, "Baseline and Projected Future Carbon Storage and Greenhouse-Gas Fluxes in Ecosystems of Alaska", USGS Professional Paper 1826, ISSN 1044-9612 (print), ISSN 2330-7102 (online)http://pubs.usgs.gov/pp/1826/pp1826.pdf
Extract of the last paragraph in the main body of the report: "The results of our synthesis have implications for carbon management strategies that might be implemented as part of national policies aimed at controlling the rate and overall magnitude of climate change. These results suggest that Alaska could be a sink for greenhouse gases under some climate scenarios, but under others it could be a source, depending on the response of CH4 emissions of lakes. However, it is important to recognize that CH4 emissions from lakes have not been considered in this assessment, and it is likely that Alaska would be a source of greenhouse gases under all climate simulations if these emissions were considered in the assessment. Models have recently been developed for simulating CH4 emissions of arctic lakes (Tan and others, 2015), and these models may be useful for estimating regional CH4 emissions of lakes in Alaska in future assessments to more fully inform policy decisions concerning the mitigation of greenhouse-gas emissions in the United States."