How will climate change affect the US?

[BillTre]

TL;DR Summary

Several Maps are published about how climate change might play out in the 48 contiguous US states.

Several maps, from ProPublica, showing how climate change may play out as changes in the US.

According to new data from the Rhodium Group analyzed by ProPublica and The New York Times Magazine, warming temperatures and changing rainfall will drive agriculture and temperate climates northward, while sea level rise will consume coastlines and dangerous levels of humidity will swamp the Mississippi River valley.

Note: Wet bulb, sea level rise, crop yield and economic damage data represent ranges of median probabilities for each county modeled by the Rhodium Group for each climate scenario between 2040 and 2060. Sources: Chi Xu, School of Life Sciences, Nanjing University (global human climate niche), Rhodium Group/Climate Impact Lab (wet bulb, heat, crop yields and economic damages), John Abatzoglou, University of California, Merced (very large fires). Noun Project icons by Adrien Coquet, Laymik and ProSymbols

Lessor amounts of similar data can be found in this PNAS publication.

Some of the maps are interactive (different levels of continued emissions).
The maps cover:

• temperature/humidity based most optimal human niche areas (2070)
• extreme heat areas (weeks above 95˚ F) (2040-2060)
• Extreme heat and humidity (2040-2060)
• Large Wild Fires (2040-2071)
• Sea Level Rise (2040-2060)
• Farm Crop Yields (2040-2060)
• Economic Damage from Climate Change (2040-2060)

There is also a big table summarizing the various data county by county in the US.

Many of the maps seem to be based on counties and therefore some of the mappings of effects are not fine enough grained to satisfy me. For example, the county I live in (Lane county, Oregon), has coastal areas that could be affected by sea level rise, but not where I live (40 miles away and on the inland side of the coastal range). Nevertheless, I find it interesting.

 

[Vanadium 50]

Why did they pick those variables and only those variables? Why not, e.g. "deaths from extreme cold"? Perhaps more relevantly, Atlantic hurricanes. Models predict a lower rate, which is exactly what we see. However, it conflicts with the overly-simplistic story of "Hurricanes are from Global Warming!" and indeed identifying of individual hurricanes caused by global warming.

Predicting 50 years out is a tough business. How has the IPCC done thus far? I would give the first report a C or C-. It is possible we're consistent with the extreme lower edge (we keep falling in and out of it; I think we're in at the moment but we could be mistaken). It's probable that we are doing better now, but the argument "Thirty years ago we had trouble with thirty year predictions, but we're doing better now - just you wait and see!" is not very convincing. Had there been a little more humility and less faith in our models then we would be better off now.

Things are very complex, and it's good that they are trying to capture this complexity, but they have a long way to go.

 

[Genava]

Perhaps more relevantly, Atlantic hurricanes. Models predict a lower rate, which is exactly what we see.

From NOAA page about Global Warming and Hurricanes. An Overview of Current Research Results:

On the other hand, Swanson (2008) and others noted that Atlantic hurricane power dissipation is also well-correlated with other SST indices besides tropical Atlantic SST alone, and in particular with indices of Atlantic SST relative to tropical mean SST (e.g., Figure 1b from Vecchi et al. 2008). This is in fact a crucial distinction, because while the statistical relationship between Atlantic hurricanes and local Atlantic SST shown in the upper panel of Figure 1 would imply a very large increases in Atlantic hurricane activity (PDI) due to 21st century greenhouse warming, the alternative statistical relationship between the PDI and the relative SST measure shown in the lower panel of Figure 1 would imply only modest future long-term trends of Atlantic hurricane activity (PDI) with greenhouse warming. In the latter case, the alternative relative SST measure in the lower panel does not change very much over the 21st century, even with substantial Atlantic warming projections from climate models, because, crucially, the warming projected for the tropical Atlantic in the models is not very different from that projected for the tropics as a whole.


A key question then is: Which of the two future Atlantic hurricane scenarios inferred from the statistical relations in Figure 1 is more likely? To try to gain insight on this question, we have first attempted to go beyond the ~50 year historical record of Atlantic hurricanes and SST to examine even longer records of Atlantic tropical storm activity and second to examine dynamical models of Atlantic hurricane activity under global warming conditions. These separate approaches are discussed below.

https://www.gfdl.noaa.gov/global-warming-and-hurricanes

How has the IPCC done thus far?

In January, NASA made a claim based on one of its study:
https://climate.nasa.gov/news/2943/...are-getting-future-warming-projections-right/

And I remember CarbonBrief made an article on the topic too: https://www.carbonbrief.org/analysis-how-well-have-climate-models-projected-global-warming

 

[PeterDonis]

Thread closed for moderation.

 

[berkeman]

After a Mentor discussion, the thread will stay closed. We don't have the expertise currently in the Mentor ranks to Moderate threads that are trying to predict where the current Climate Change will lead. Sorry about that. Interesting thread start, though, IMO.