Sentences with phrase «committed warming»
"Committed warming" refers to the long-term increase in global temperature that is already guaranteed due to the accumulated emissions of greenhouse gases. This warming is certain to happen regardless of any future efforts to reduce emissions. In other words, it's the warming we cannot avoid because of the past and present levels of greenhouse gas emissions. Full definition
The paper claims that ESS is ~ 9ºC and that this implies that the long term committed warming from today's CO2 levels is a further 3 - 7ºC.
realclimate.org
In our paper, I argue that we can not rule out the possibility that there may be long - term commited warming in AOGCMs at even lower climate sensitivity.I think the TCR / ECS ratio (or realized warming fraction) is key here to understand the long - term climate response.
Among other things, the author [of the Economist's report] hopelessly confuses transient warming (the warming observed at any particularly time) with committed warming (the total warming that you've committed to, which includes warming in the pipeline due to historical carbon emissions).
Part II of this series will look at a new paper published recently in PNAS on committed warming, which I think, once explained, will blow your mind...
Mauritsen T. and R. Pincus (July 2017): Committed warming inferred from observations.
(see also, Gavin's keypost addressing the distinction between «pipelined», or previously committed warming assuming constant CONCENTRATION, as contrasted with the complete cessation of combustion:)
Fellow US climate expert Michael Mann emailed the the ThinkProgress website, arguing that: «the author hopelessly confuses transient warming (the warming observed at any particularly time) with committed warming (the total warming that you've committed to, which includes warming in the pipeline due to historical carbon emissions).»
The paper claims that ESS is ~ 9ºC and that this implies that the long term committed warming from today's CO2 levels is a further 3 - 7ºC.
Furthermore, on committed warming: Even though warming is only 7 / 10ths of a degree so far, we are committed to almost 1.5 degrees Celsius due to how long it will take the oceans to catch up.
Pincus authored the analysis of committed warming, along with Thorsten Mauritsen of the Max Planck Institute for Meteorology.
Re; # 36: Raypierre says: «except to say that over a time scale of «a hundred years», some heat does mix down to a depth of around 300m, which is why we have «committed warming» in the pipeline»
So, I think he is considering not just stabilizing at committed warming but actually avoiding some of that.
Mike Roddy has referred to many times before in here; the feedback loops, I've read terms like «Committed Warming» referring to the fact that no matter what we try to do or not do to mitigate climate change, it is still predicted to get considerably warmer for at least the next 100 years.
According to «conventional climate science» the currently already emitted amount of CO2 (404 ppm) leads to a committed warming of 1.56 degrees Celsius.
(The faster the ocean is currently taking up heat, the greater the amount of «committed warming» that will occur after GHGs stop rising.)
Effectively, the forcing «felt» by the climate system is only 53 %, i.e., 1.3 °C, which is identical to CEW G A, the committed warming adapted by earlier studies.
Many of the «committed warming» scenarios are actually for constant composition: so rather than emissions dropping to zero, emissions stay at a low level to maintain the current CO2 concentrations.
To leap from that to the claimed 3 - 7ºC warming requires that the changes in the ice sheets and vegetation arising from the current and (medium term) committed warming would increase the radiative imbalance by another ~ 2 W / m2 — and that is extreme (for reference, the changes between the last ice age and now from these factors is only about 4 W / m2 (Kohler et al, 2010) with the huge impact of the N. American and European ice sheets included).
A Google Map tour lead by Governor Arnold Schwarzenegger shows the risks like water shortages and wild fires, and highlights what the state is doing legislatively to focus on preventing climate change, and managing the problems we're already bound to experience due to committed warming.
The current energy imbalance (just a little less than 1 W / m2) implies that the planet would need to warm by ~ 1 x S / 3.7 ºC to restore an equilibrium, and using the standard climate sensitivity of 3ºC for a doubling of CO2, implies a committed warming of 0.8 ºC or so.
Thus, Snyder's claim of a committed warming of 3 - 7ºC is based on an incorrect method for defining ESS, an inappropriate application of this to the present and is inconsistent with current estimates of the radiative imbalance and plausible future changes in ice sheets.
So, what do we think the ESS is, and how does that impact our view of committed warming today?
``, and using the standard climate sensitivity of 3ºC for a doubling of CO2, implies a committed warming of 0.8 ºC or so.»