Bam wrote on Oct 1
st, 2018 at 11:59pm:
lee wrote on Oct 1
st, 2018 at 7:48pm:
BTW - New paper
"Earth’s outgoing longwave radiation linear due to H2O greenhouse effect"
"The team found this linear relationship breaks down when Earth’s global average surface temperatures go much beyond 300 K, or
80 F. In such a scenario, it would be much more difficult for the Earth to shed heat at roughly the same rate as its surface warms.
For now, that number is hovering around 285 K, or
53 F. "
http://news.mit.edu/2018/how-earth-sheds-heat-space-0924Only 26F before it breaks down. Apparently .
And H2O controls temp? oh dear.
That's why it's called a "runaway greenhouse." Once the water vapour starts making a critical contribution, it is game over because it accelerates in a positive feedback. It won't stop until the oceans boil away and are lost to space. When does that happen? Nobody knows for sure but it could be closer than we think.
Do you want to see the future of this planet? Look at Venus. Earth will be like that one day. If human activity wasn't contributing, Earth will become uninhabitable between one and two billion years from now due to increased solar activity. That cannot be stopped. However, it can be accelerated, and that's what is happening right now. That's why we need to turn down the thermostat.
The worst part is not what we know. It's what we
don't know. What happens when we warm up the permafrost where a lot of methane is trapped? What happens if the methane clathrates in the oceans start escaping? How much warming before it becomes irreversible?
The thing I don't like about both sides on the MMGW debate is when they make outlandish claims about how bad the earth's climate will become. Whether you're on the anti MMGW side claiming the earth will enter a new ice age and become a giant popsicle due to the expectations of a prolonged solar minimum after Solar Cycle 25, or whether you're on the pro MMGW side claiming average global temperatures will be similar to Venus, you are not doing your side justice by making claims that have no basis based on the current data available. All you do is turn people away from your hypothesis and any chance to enact policies to mitigate the probable effects of the change in climate will diminish.
Based on current data, if we burnt all of the fossil fuels on earth, which based on current rates of consumption will take a few hundred years at the earliest, it is estimated that average global temperatures will rise by about 10 degrees C, which will raise ocean levels by about 50 metres. Given that within the next 30 - 40 year we will have developed energy technologies that will dramatically reduce, even eliminate, our reliance on carbon based fuels, I doubt that such a scenario will be achieved.
However, I am unsure whether or not this factors in the effects of melted Arctic Permafrost. There is still a degree of debate as to what effect this melted permafrost will have. Again, if energy technologies develop that will reduce or eliminate our reliance on carbon based fuels this will stop further increases of CO2 in the atmosphere, which will reduce the possibility of the Arctic Permafrost melting.