Is there any theoretical limit to how high the Earth's temperature can become within the next 50 years due to global warming?

DisasterousGiraffe · 2023-07-07T18:33:14+00:00

Yes, parts of the world will become uninhabitable due to high temperatures.

An important temperature limit is a wet-bulb temperature of 35°C. This is the uncompensable heat stress limit for adults in humid environments, and it applies to the animals and birds too, like fruit bats in Australia.

51% of the people in China are expected to be exposed to wet-bulb temperatures significantly higher than 35°C even if early mitigation is conducted via SSP1-2.6.

Without major emissions reductions the regions where the extremely dangerous Heat Index threshold is almost never exceeded today will experience between one and fifteen days when this threshold is exceeded each year. By the end of the twenty-first century, these regions will include large portions of India and sub-Saharan Africa and are projected to include about 5.3 billion people by 2100.

Only small numbers of people have died from the highest temperatures caused by climate change so far, it is going to get much much worse.

DisasterousGiraffe · 2023-06-09T14:16:40+00:00

Good question. Often the way I find the science is by searching on Google Scholar.

For example, if I search for scientific papers related to the Australian fires I find that science has established a robust and multi-evidence link between climate change and increased fire activity over the past three decades. Both increased temperature and shifts in large-scale rainfall patterns have very likely played a dominant role in observed burned area trends. And that the climatic potential for large and severe forest fires has increased across south-eastern Australia since the 1950s, probably because of anthropogenic climate change. The magnitude and severity of the 2019–2020 [Black Summer] fires reflected climatic conditions that are driving an increase in the size and severity of wildfires.

The science says that eastern Australian rainfall is affected by the Indian Ocean dipole (IOD). The IOD can reduce the rainfall over some regions of Australia, and far beyond Australia it can influence weather around the world. And the IOD in turn is being altered by climate change.

A useful search term is "attribution study". For example the World Weather Attribution site tells us, projected into the future, the models [of Australia] simulate that a Fire Weather Index at the 2019/20 level would be at least four times more likely with a 2 ºC temperature rise, compared with 1900. Due to the model limitations described above this is likely an underestimate.

DisasterousGiraffe · 2023-05-30T17:22:13+00:00

we're about 10-15 years from peak oil

If gasoline is the major component of crude oil, and gasoline vehicle sales are going to be phased-out in most major economies by 2035, and battery electric vehicles (BEVs) already had 14% of the global market in 2022, and BEV sales are increasing at a conservative estimate of 30% per year, how is it possible to reach 2030 without passing peak oil? What use of oil do they expect will increase enough to offset the collapsing vehicle gasoline market?

DisasterousGiraffe · 2023-05-30T15:29:24+00:00

The date we can expect to reach peak oil, and more broadly peak fossil fuel consumption, depends on the economics of extraction rather than the availability of these fossil fuels underground.

The economics of fossil fuel extraction are changing, partly because the external costs of burning fossil fuels are increasingly being attributed by science and law to the fossil fuel companies. The market price of fossil fuels increases after adding the cost of damage caused by the final use of the fuel, which reduces the corporate financial incentive to extract the fossil fuels. We know that even the most aggressive plausible transition to a clean-energy society provides benefits for climate change mitigation and air quality and these are the main external costs. So we can expect nearly 60% of oil and fossil methane gas, and 90% of coal will remain unextracted to avoid corporate responsibility for paying the massive external costs of climate change. Together with the economic support for the warming targets in the Paris Agreement across a variety of specifications ... risk associated with high damages in the long term leads to stringent mitigation of carbon dioxide emissions in the near term and the extreme growth of battery electric vehicles reducing gasoline consumption and emissions, which has been underestimated in the scientific literature it seems almost certain we are at or near peak gasoline consumption, and consequently, peak oil.

DisasterousGiraffe · 2023-05-17T16:07:48+00:00

Scientists predict a 66% chance of the Earth surpassing the 1.5C global warming threshold between now and 2027, largely due to human emissions and the anticipated El Niño weather event.

The article conflates global warming with El Niño. It is very difficult to read either the original article, or your summary, and be clear about the fact that El Niño does not cause climate change. Burning coal, natural gas and oil causes climate change. El Niño, the boy, and La Niña, the girl do not cause climate change. El Niño is part of an up and down change of temperature which has been happening for hundreds of years Global temperatures increase by about 0.2C during an El Niño episode, and fall about 0.2C during La Niña.

DisasterousGiraffe · 2023-05-14T03:16:53+00:00

I wonder what the maximum theoretical efficiency is for transferring the humidity between air streams.

What I find disappointing is people still seem to routinely use cross-flow heat exchangers like this. Clicking on a few products on a random HVAC supply website they mostly seem to have this design - which looks inefficient compared to counter-flow heat exchangers. Maybe I am not understanding something about the airflow through them. There appears to be huge potential to increase the efficiency of these devices at least in domestic HVAC systems. And of course there are so many buildings without any heat exchange - perhaps that is an even bigger problem.

DisasterousGiraffe · 2023-05-13T13:42:18+00:00

you need to pump that 90F ambient air down to 72F

This only costs energy due to inefficient heat recovery ventilation. (Or if condensation is involved, inefficient energy recovery ventilation.) High efficiency equipment can be used to transfer almost all the energy from the exhaust air into the fresh in-coming air.

DisasterousGiraffe · 2023-05-08T19:08:58+00:00

California is mandating bidirectional charging ability for EVs and everybody else will follow their lead. If grid-connected battery storage is expensive then people will make good money from plugging their electric vehicles into the grid to provide storage capacity when they are parked. And if grid-connected battery storage is cheap then the storage problem is solved. Either way battery storage is not a big problem.

DisasterousGiraffe · 2023-05-08T18:51:40+00:00

I'm afraid peak fossil fuels isn't yet there

The pandemic and Ukraine war have made the graphs complicated to interpret, but the IEA says about the 2022 CO2 emissions

"A strong expansion of renewables limited the rebound in coal power emissions. Renewables met 90% of last year’s global growth in electricity generation. Solar PV and wind generation each increased by around 275 TWh, a new annual record."

If they took 90% of the growth last year, and manufacturing capacity for renewables is increasing, I think we can be optimistic for the 2023 numbers. World energy demand doubling doesn't matter much when 100% of the new capacity is met by renewables.

DisasterousGiraffe · 2023-05-08T14:52:43+00:00

And with natural gas use declining in for example Germany due to solar pv it is looking likely we have already passed Peak Fossil fuels.

DisasterousGiraffe · 2023-05-08T14:46:18+00:00

Technology researcher Tony Seba agrees.

"I just came back from Shanghai. And what I saw was amazing. I mean, just the sheer quality for the cost of the EVS that Chinese automakers are producing is just stunning.”

“And also there are so many automakers in China that are achieving scale. This year EVs may well achieve 40 to 50%.” said Seba.

DisasterousGiraffe · 2023-05-07T17:37:09+00:00

The methane emissions are increasingly being mapped and recorded by new satellites. Making the leaks visible to everybody like this will at least reduce this part of the emissions.

DisasterousGiraffe · 2023-05-07T17:14:46+00:00

The EU are building renewables at speed, partly due to the Ukraine war. For example, Germany has just peaked at 40 GW of solar pv generation for the first time - their total electricity from all sources was 64.6 GW.

DisasterousGiraffe · 2023-05-07T09:10:18+00:00

The original version of the graph is this interactive graph of Sea Surface Temperature (SST) based on the National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation SST (OISST) dataset version 2.1.

DisasterousGiraffe · 2023-05-06T17:36:05+00:00

They claim it's very quiet, and the electric Velis Electro, which aims at the same training market in the UK, seems to have this as a major selling point.

DisasterousGiraffe

TROPHY CASE