Optimistically. Within 25 years, tens of millions of people will have been displaced by sea level rise due to global warming. If you think all those people, and the countries they live in, are going to go quietly into the night, you are a fool.

Current projections suggest a sea level rise of at least one metre this century is now likely. A one-metre rise will displace at least 56 million people, and possibly double that.

From Bangladesh to the Maldives, from Vietnam to Pakistan to Alexandria to Venice, millions upon millions of people will be driven from their homes and livelihoods. And where are they to go? Into ever-more crowded areas of their own – and neighbouring – countries. Rising sea levels will produce a tide of climate refugees that will make the chaos in Darfur look mild.

Many of those refugees, and the people whose lands they attempt to crowd into, are going to be angry. Combine that with nothing left to lose, and we have a recipe for human-caused Armageddon. Their governments will be driven to extreme actions, such as unauthorized and desperate attempts at geo-engineering, or capturing and probably executing climate deniers like Rex Tillerson, CEO of ExxonMobil, which continues to this day to fund climate denial – to bankroll, in effect, the dispossession and death of millions.

Scientists tend to talk about long-term projections, as these have the most certainty. However, long before the sea rises one metre by 2100, many millions will have been displaced and many hundreds of millions will see their future clearly – they will lose everything: Their land and farms, their businesses, their livelihoods – virtually everything of any value.

I give us a maximum of 25 years before mass riots begin, and probably wars. Within 25 years, sufficient millions will have been dispossessed or drowned by sea level rise alone – not considering other impacts of climate change like stronger storm surges, desertification, the spread of malaria-carrying mosquitoes, and so on and on – that everyone else will know the bell tolls for them, too.

The world will become a very hostile place. No longer will Americans slap Canadian flags on their luggage when touring the world, because all developed countries will be reviled. Canada, the United States, and the United Kingdom will be especially loathed, as we are the countries that have spewed the most greenhouse gases, that continue to do so, and that refuse to change because we are too greedy.

(Another very likely outcome of climate change will be the end of American capitalism and a rise in religious fundamentalism, as people return to values that recognize greed as a sin, not as a virtue.)

You have, at best, 25 years to see the world, to experience different cultures, to remember the world as it is and could have been. After that, if you have a home, it will be safest to spend the remainder of your days there.

More articles on Celsias:

Review: Lester Brown's New Plan B

America's Water Supply: Scarcity Becoming Endemic

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