4 ms·

> "A lot of your coastal historical cities are going be be underwater and parts of your country will become uninhabitable, meaning you and everyone else will ne

by timmg 3y ago

> "A lot of your coastal historical cities are going be be underwater and parts of your country will become uninhabitable, meaning you and everyone else will need to move elsewhere" is absolutely horrific. Which cities and what timeline are you talking about? Sea level has risen like a half a foot in the last 70 years. That's not all that fast. Meanwhile, places like Netherlands are increasing their land area over that time.

acdha 3y ago
How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? They probably aren’t going to end up permanently underwater but everything suggests a lot of pricey real-estate is going to end up getting washed away (California already has billions of dollars in real estate threatened by erosion) or regularly flooded. There’s no realistic long-term outcome other than relocating from the affected areas and letting them become buffer parks (hopefully with lush mangroves in Florida). That’s in a rich country with a lot of resources, and at least a history of helping other states out. Bangladesh is facing another climate change-boosted storm but has thousands of people who are still homeless from last year’s storm which also hammered food production. That’s the kind of scenario where things get ugly because millions of people live in areas which will see the worst impacts but lack anything like the resources to harden infrastructure or relocate large numbers of people.
- katbyte 3y ago
  > rebuild Miami after bigger hurricanes do more damage Miami will likely end up mostly underwater and dykes and seawalls will not be able to protect it. The city is built on porous limestone that will allow seawater to just bypass them unless you dig down past that limestone bedrock layer.
- timmg 3y ago
  > How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? We have continued to build in disaster-prone areas. That's a real problem. But that is somewhat orthogonal to climate change. Imagine a world without climate change. Are there still hurricanes? Is Miami still a low-lying city in a high-hurricane area? Do we continue to build more condos there? Imagine a world without climate change and ask again: How much more are you willing to pay to rebuild Miami after "a big" hurricane does damage?
- mdorazio 3y ago
  You didn’t really respond to the parent comment’s question. Sea level around Miami will rise about a foot over the next thirty years and a little over an additional foot over the following 30 years [1]. Most of Miami is about 6-8 feet above sea level. So again, what timeline are you worried about? Other parts of the Florida coast are definitely screwed, though (ex. The Keys). [1] https://climatecenter.fsu.edu/topics/sea-level-rise https://climatecenter.fsu.edu/topics/sea-level-rise
  - pyrale 3y ago
    The rise is a mean. That means that high tides, water surges due to storms, etc. will also be amplified. If you consider the current risk of flooding as a stochastic process, moving the mean may result in an exponential risk increase.
  - WorldMaker 3y ago
    Most of Miami is 6-8 feet today because Miami has had mayors (mostly democrats) for multiple decades now that took climate change seriously, made it a core part of city planning, and overall, in general, the city paid a lot of money to avoid some of the most egregious mistakes ahead of time in its infrastructure. "Miami is going to be fine, mostly" isn't a slam dunk argument that climate change won't have real impacts, because Miami has already been fighting against it. (A lot of the rest of Florida has more to worry about in part because they haven't been nearly as proactive.)
  - acdha 3y ago
    Yes, we’re not going to rename it to New Atlantis with submarine tours but that doesn’t mean everything is fine. Storm surges are the most dramatic problem since the max matters more than the median for where you can build things, but there are other problems around the water table rising and septic systems. Flooding of low roads, parks, etc. is common even without storms and storm flooding can take longer to drain, too. Before they moved, some family members saw hefty increases for insurance premiums and restricted coverage – and that trend is just getting started. Each of the things which needs to be hardened or redesigned costs billions, and there’s no guarantee that those projects will be enough, or that there won’t be other impacts on the economy if, say, popular tourist beaches aren’t as attractive due to erosion or some hotels are severely damaged.
- Turing_Machine 3y ago
  > How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? There is no evidence that hurricanes are getting bigger or more frequent. If anything, the record shows the opposite. https://www.nhc.noaa.gov/pastdec.shtml https://www.nhc.noaa.gov/pastdec.shtml Edit: this data set goes through 2022 (the previous chart only went up to 2004) https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.html https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.htm...
  - acdha 3y ago
    The scientific consensus is that hurricanes will be stronger and wetter, but it’s complicated to say exactly what that means regionally since there’s considerable natural variation and we have limited historical records for most of the oceans and many regions which weren’t historically densely populated. There’s a good overview here which discusses different aspects and the confidence levels on predictions both globally and for the Atlantic: https://www.gfdl.noaa.gov/global-warming-and-hurricanes/ https://www.gfdl.noaa.gov/global-warming-and-hurricanes/
pyrale 3y ago
> Sea level has risen like a half a foot in the last 70 years. That's not all that fast. The pace of ice melting is still an unpredictable process due to its non-linearity, but the current imbalance between ice melting and new snow in the Greenland ice sheet commits a 27cm rise, according to [1]. This with current temperatures (not temperature rises). From my layman understanding, antarctic runoff is less understood, but also its effect is potentially much larger. Article : [2] Finally people with more knowledge than me, IPCC AR6, have estimates based on paleoclimates that depend on climate trajectory. [3], box TS4 pp. 77-78. Their optimistic story is 28-55cm by 2100. Their pessimistic assessment is "Under the higher CO2 emissions scenarios, there is deep uncertainty in sea level projections for 2100 and beyond". Also note that even in the best scenario, sea doesn't stop rising after 2100. Sea level rise is likely locked in for centuries. A last word on "mean sea level": it's just a mean, impact may be worse for some areas. > Meanwhile, places like Netherlands are increasing their land area over that time. That's, like, a tiny confetti of wealthy people. Not sure this kind of anecdotal information is relevant to rising sea levels. [1] https://www.nature.com/articles/s41558-022-01441-2 https://www.nature.com/articles/s41558-022-01441-2 [2] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019RG000663 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201... [3] https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_TS.pdf https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6...

by timmg 3y ago

acdha 3y ago

How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? They probably aren’t going to end up permanently underwater but everything suggests a lot of pricey real-estate is going to end up getting washed away (California already has billions of dollars in real estate threatened by erosion) or regularly flooded. There’s no realistic long-term outcome other than relocating from the affected areas and letting them become buffer parks (hopefully with lush mangroves in Florida). That’s in a rich country with a lot of resources, and at least a history of helping other states out. Bangladesh is facing another climate change-boosted storm but has thousands of people who are still homeless from last year’s storm which also hammered food production. That’s the kind of scenario where things get ugly because millions of people live in areas which will see the worst impacts but lack anything like the resources to harden infrastructure or relocate large numbers of people.

katbyte 3y ago
> rebuild Miami after bigger hurricanes do more damage Miami will likely end up mostly underwater and dykes and seawalls will not be able to protect it. The city is built on porous limestone that will allow seawater to just bypass them unless you dig down past that limestone bedrock layer.
timmg 3y ago
> How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? We have continued to build in disaster-prone areas. That's a real problem. But that is somewhat orthogonal to climate change. Imagine a world without climate change. Are there still hurricanes? Is Miami still a low-lying city in a high-hurricane area? Do we continue to build more condos there? Imagine a world without climate change and ask again: How much more are you willing to pay to rebuild Miami after "a big" hurricane does damage?
mdorazio 3y ago
You didn’t really respond to the parent comment’s question. Sea level around Miami will rise about a foot over the next thirty years and a little over an additional foot over the following 30 years [1]. Most of Miami is about 6-8 feet above sea level. So again, what timeline are you worried about? Other parts of the Florida coast are definitely screwed, though (ex. The Keys). [1] https://climatecenter.fsu.edu/topics/sea-level-rise https://climatecenter.fsu.edu/topics/sea-level-rise
- pyrale 3y ago
  The rise is a mean. That means that high tides, water surges due to storms, etc. will also be amplified. If you consider the current risk of flooding as a stochastic process, moving the mean may result in an exponential risk increase.
- WorldMaker 3y ago
  Most of Miami is 6-8 feet today because Miami has had mayors (mostly democrats) for multiple decades now that took climate change seriously, made it a core part of city planning, and overall, in general, the city paid a lot of money to avoid some of the most egregious mistakes ahead of time in its infrastructure. "Miami is going to be fine, mostly" isn't a slam dunk argument that climate change won't have real impacts, because Miami has already been fighting against it. (A lot of the rest of Florida has more to worry about in part because they haven't been nearly as proactive.)
- acdha 3y ago
  Yes, we’re not going to rename it to New Atlantis with submarine tours but that doesn’t mean everything is fine. Storm surges are the most dramatic problem since the max matters more than the median for where you can build things, but there are other problems around the water table rising and septic systems. Flooding of low roads, parks, etc. is common even without storms and storm flooding can take longer to drain, too. Before they moved, some family members saw hefty increases for insurance premiums and restricted coverage – and that trend is just getting started. Each of the things which needs to be hardened or redesigned costs billions, and there’s no guarantee that those projects will be enough, or that there won’t be other impacts on the economy if, say, popular tourist beaches aren’t as attractive due to erosion or some hotels are severely damaged.
Turing_Machine 3y ago
> How much more are you willing to pay to rebuild Miami after bigger hurricanes do more damage? There is no evidence that hurricanes are getting bigger or more frequent. If anything, the record shows the opposite. https://www.nhc.noaa.gov/pastdec.shtml https://www.nhc.noaa.gov/pastdec.shtml Edit: this data set goes through 2022 (the previous chart only went up to 2004) https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.html https://www.aoml.noaa.gov/hrd/hurdat/All_U.S._Hurricanes.htm...
- acdha 3y ago
  The scientific consensus is that hurricanes will be stronger and wetter, but it’s complicated to say exactly what that means regionally since there’s considerable natural variation and we have limited historical records for most of the oceans and many regions which weren’t historically densely populated. There’s a good overview here which discusses different aspects and the confidence levels on predictions both globally and for the Atlantic: https://www.gfdl.noaa.gov/global-warming-and-hurricanes/ https://www.gfdl.noaa.gov/global-warming-and-hurricanes/

pyrale 3y ago

> Sea level has risen like a half a foot in the last 70 years. That's not all that fast. The pace of ice melting is still an unpredictable process due to its non-linearity, but the current imbalance between ice melting and new snow in the Greenland ice sheet commits a 27cm rise, according to [1]. This with current temperatures (not temperature rises). From my layman understanding, antarctic runoff is less understood, but also its effect is potentially much larger. Article : [2] Finally people with more knowledge than me, IPCC AR6, have estimates based on paleoclimates that depend on climate trajectory. [3], box TS4 pp. 77-78. Their optimistic story is 28-55cm by 2100. Their pessimistic assessment is "Under the higher CO2 emissions scenarios, there is deep uncertainty in sea level projections for 2100 and beyond". Also note that even in the best scenario, sea doesn't stop rising after 2100. Sea level rise is likely locked in for centuries. A last word on "mean sea level": it's just a mean, impact may be worse for some areas. > Meanwhile, places like Netherlands are increasing their land area over that time. That's, like, a tiny confetti of wealthy people. Not sure this kind of anecdotal information is relevant to rising sea levels. [1] https://www.nature.com/articles/s41558-022-01441-2 https://www.nature.com/articles/s41558-022-01441-2 [2] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019RG000663 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/201... [3] https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_TS.pdf https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6...