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Comment by chadash | Hacker News Reader

The NOA predicts sea level rise of 2 feet by 2100. There might be small chunks of the Everglades on the Southern tip of Florida that are 2 feet or lower, but I believe the vast majority of the Everglades are 10 feet or higher. We probably won't see that in our lifetimes.

This isn't to downplay climate change or the risk of rising sea levels. These are very real, but I think that many people overestimate it. Even for Miami, which is very elevation, I don't think we will see it underwater... but we will see lots of flooding since the sewage systems won't be able to drain when the ocean level gets too close to the land. This already happens, but it will get worse.

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> I believe the vast majority of the Everglades are 10 feet or higher

The Everglades are 0-8 ft[1] above sea level and average depth of the water is 4-5 ft[2]. If that elevation is measured at the surface of the water, then it would only take a few feet of sea-level rise to contaminate the Everglades.

> Even for Miami, which is very elevation, I don't think we will see it underwater

Most of Miami-Dade County was projected to be under water by 2060[3], and that was before the recent discovery that glaciers are melting much faster than we expected[4].

1. https://www.nps.gov/ever/learn/news/parkstatistics.htm

2. http://www.waterencyclopedia.com/En-Ge/Everglades.html

3. https://www.cbsnews.com/miami/news/scientists-warn-south-flo...

4. https://www.washingtonpost.com/climate-environment/2023/05/0...

As others have noted 2 feet is the low end of the estimate, but the threat isn't just from land lost to sea level rise, that's the.

The first thing you'll notice living in Florida is coastal flooding, but the imminent and more pressing danger is salt water intrusion. You don't need to cover all the surface of land with water for that happen. If sea levels rise only 2 feet the fresh water sources along the coasts are threatened from salt water coming in from the sides. Florida is particularly vulnerable because it has very porous limestone geology. This geology allows for deeper interior advancement of salt water compared to other coastal areas, meaning less sea level rise is required for large fresh water impacts

Here's a good visualization on what salt water intrusion is https://blogs.egu.eu/network/gfgd/2018/02/12/saltwater-intru...

Here's an article specifically about the threat to Florida's drinking water https://cnsmaryland.org/2020/11/23/salt-levels-in-floridas-g...

Is this the report you are referring to? https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelr... It carefully says two feet if we curb emissions in the future - are they claiming we could agree on a freeze in the USA (as we are number one!) and developing large nations(China), but it will be many times higher but unpredictably so otherwise. It's also a year old and doesn't reflect the latest news on Greenland and Antarctic glaciers melting much faster than expected.

  Everglades restoration would also help the aquifer fight off rising seas that make it vulnerable to saltwater intrusion and pollution caused by run-off from agricultural lands and residential areas.
  
  “Restoration is key because when water can once again move north to south, more clean water can fill up the Everglades and the aquifer, allowing fresh water to push back the salt water,” Crowl says.

I don't know what your source is for the 2 ft number, as any predictions of future sea level are dependent on emissions scenarios. Further, sea level is local--that is, different areas of the world will experience different amounts of local sea-level rise in the future, based on regional conditions.

In south Florida, the estimated sea-level rise for the intermediate-high emissions scenario is approximately 5.5 feet by 2100. Attaining 2 feet of SLR requires an intermediate-low scenario. The high scenario results in 7 feet.

A nice viewer is here: https://coast.noaa.gov/slr

Storms will also get worse and more frequent, so I assume storm surges will get worse as well.

Worse and less frequent

https://sciencecouncil.noaa.gov/wp-content/uploads/2023/05/1...

I was imprecise. I meant the worse storms would get more frequent. My point was that more frequent bad storms combined with modest sea level increase meant greater chance for overrun compared to just the sea level increase.

This is noted in the document you linked to, where they mention most of the models project an increase in of Atlantic hurricanes reaching Category 4 or 5 even at an optimistic 2 degree C rise. They do note it's somewhat uncertain though, I'll give you that.

Under normal conditions it won't flood, but there's definitely a risk during extreme weather like a hurricane where there's tidal swells

> Even for Miami, which is very elevation

I was going to make a refined criticism but this typo makes it clear - neither you nor anyone else knows what is happening with sea level rise. Why question "NOA" - named NOAA ? because of recent activity in the western antarctic ice shelf.

sorry to dismiss this comforting thought, but no, nobody knows what the sea levels will be in the year 2100 -- this is a serious situation and it is getting worse now.

I'm guessing the models are extra conservative and there's going to be some oopsies in how it plays out. I'm not a climate scientist but it's already clear that things are happening faster than earlier predictions.

What's doubly distressing is that it's been so highly politicized. I'm not $ure why that i$...

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