Update: The subject of climate change came up again during Thursday night's Republican debate, which was also held in Miami. We are re-upping the below post from earlier in the day.

At the moment that I write this, the measured water levels at Virginia Key, Fla., are about eight inches above predicted levels. In January, levels were regularly a foot or more above predicted levels.

The sensor station at Virginia Key is located just off the coast of Miami, just south of Miami Beach, where rising sea levels mean that the streets flood regularly. So regularly that it's been covered by The Post, the Times and the Miami Herald — and likely many others.

"The city of Miami Beach floods on such a predictable basis," Elizabeth Kolbert wrote for the New Yorker last December, "that if, out of curiosity or sheer perversity, a person wants to she can plan a visit to coincide with an inundation." The day the issue was released, sea levels were eight inches above the projection.

Miami is also where the most recent Democratic debate was held on Wednesday night, and the topic of climate change came up.

sea-level-download2-2015

At its root, the flooding is a function of climate change. Warmer temperatures caused by the greenhouse effect cause glaciers to melt, increasing the amount of water in the ocean. Those warmer temperatures also cause the water in the ocean itself to expand, the same way that the surface level of water heated on a stove will rise in a saucepan. Sea levels have risen several inches near Miami since 1960, according to data from the National Oceanic and Atmospheric Administration.

At the debate, The Washington Post's Karen Tumulty, serving as a moderator, noted that two dozen Florida mayors had requested that candidates address the subject in a debate. They wrote an open letter, asking for candidates to answer three questions: What investments will you make to protect our coastal assets and economy from the growing impacts of sea level rise and climate change?, What are specific policies you would put in place to reduce greenhouse gas emissions? and What policies would you put in place to ensure that America delivers on its commitment to reduce greenhouse gas emissions?

Tumulty's question was more direct, posed to Sen. Bernie Sanders (Vt.) first. Since Republicans refuse to act on climate change — a function of skepticism in their base and among their allies — how can climate change be addressed?

Sanders suggested that Republicans were afraid to address the subject because they were worried about losing campaign funding. Later, he called for a "tax on carbon" and for heavy investments in energy efficiency and sustainable energy. He also called for an end to fracking.

It's worth explaining each of those things. A "carbon tax" is basically what it sounds like. For large sources of carbon dioxide emissions — mostly coal-burning power plants — there would be a fee associated with those emissions. (Scientists believe that carbon dioxide emitted from burning fossil fuels stays in the atmosphere, preventing heat from escaping into space.) This is not as controversial as it sounds; a number of oil companies have backed such a tax. Energy efficiency comes at a reduction in greenhouse gases from the other side. Since energy use means more electricity production and, therefore, more burning of coal, or since more heat means more heating oil, efforts to reduce the amount of energy we use will indirectly reduce the amount of fuel we burn. Sustainable energy is wind and solar, forms of generating electricity without burning coal.

These are some of the most commonly considered ways to reduce the long-term effects of climate change. But they don't do much for Miami Beach right now.


Sea level rise simulator (NOAA)

Tumulty then offered the same question to Hillary Clinton. Clinton dropped some local knowledge about Miami Beach and mentioned the need to transition from coal to natural gas to renewable energy sources. This is her response to Sanders's no-fracking demand: Natural gas emits far less greenhouse gas when burned, making it preferable to coal. The problem is that natural gas itself is a very potent greenhouse gas that often escapes into the atmosphere as it's removed from the ground. (Also, the wastewater from fracking is injected into high-pressure wells underground, a process that has been linked to earthquakes.)

Clinton summarized her strategy: "Invest in resilience and mitigation while we are trying to cut emissions." Cutting emissions and mitigation point to the things we just discussed. She specifically referred to President Obama's Clean Power Plan which, among other things, would mandate that existing power plants limit carbon dioxide emissions.

It's the "resilience" here that's particularly interesting. The government has a toolkit to help individuals and cities prepare for the effects of climate change. Here, for example, a video about how Denver is preparing to deal with having less snow in the Rockies.

Resilience plans are necessarily localized, as this might suggest. Miami doesn't need to know what to do in the event of less water; it has too much. (Actually, that's not entirely true. Rising seas threatens to pollute Miami's freshwater supply.) Miami Beach has a robust plan, nicely outlined by Fusion, that includes sea walls, more trees, raised streets and elevated sand dunes — all of which could help block incoming sea water.

This was a level of detail we shouldn't expect from a presidential candidate in the middle of a debate, but it's critical to include in any plan. Sanders mentioned infrastructural investments that could produce new jobs; the project Miami Beach is considering certainly qualifies, but would like come further back on the priority list. Republicans and other members of Congress who are loathe to act on climate change will likely be similarly slow to bump Miami Beach's sea walls ahead of repairing a bridge on I-80.

Shortly after Hurricane Sandy, the New Yorker's James Surowiecki noted a critical political problem for any climate action. Referring to a report from economist Andrew Healy and political scientist Neil Malhotra, he writes:

Politically speaking, it’s always easier to shell out money for a disaster that has already happened, with clearly identifiable victims, than to invest money in protecting against something that may or may not happen in the future. Healy and Malhotra found that voters reward politicians for spending money on post-disaster cleanup, but not for investing in disaster prevention, and it’s only natural that politicians respond to this incentive.

Of the answers offered by Clinton and Sanders, Clinton's was more robust. But neither really answered Tumulty's question: How do you do it? How do you actually keep Miami Beach from being flooded every time the moon gets full?

Perhaps they didn't answer it, because the answer is too easy: Maybe you can't — until there's a disaster.