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JGCRI / gcam-core

GCAM -- The Global Change Analysis Model
http://jgcri.github.io/gcam-doc/
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Global mean temperature increases after a period of decrease #271

Open Sandie1994 opened 1 year ago

Sandie1994 commented 1 year ago

Hi Seniors, so in this week I have ran a bunch of low carbon and high carbon scenarios under a net zero CO2 emissions constraint by 2050. I have realized that after a decrease in temperature up to the 2080s, it begins to increase again after 2085 onwards. I checked the annual CO2 emissions, and it appears that for all scenarios net negative emissions is recorded around the 50s-80s, but after that is a continued period of positive emissions till the end of century. This observation is a bit surprising to me given that global emissions constraints have been set. It is also important to note that I have included novel CDRs albeit with an upper limit.

Another thing is, for a second group of scenarios run under forced 1.9 and 2.3 W/m2 targets, it is observed that there is almost no difference in various results across all scenarios. For example, by phasing out certain high carbon fuels from a particular sector(s), I expected to see appreciable difference in results related to the deployment of low carbon fuels in contrast to those of the high carbon fuels but in most cases the differences in results is extremely slight. I am hoping there is a way to improve the situation.

I would really appreciate some comments and suggestions on the above points and how to go about it. Thank you.

ssmithClimate commented 1 year ago

I suggest to take a look at radiative forcing by type output from hector. That should give you some indication of what is driving the behavior you are seeing.