If you're on the coast and you're anywhere near sea level, global warming spells massive trouble. From Miami to New York City, Bangladeshi coastal cities to Japanese ones, the rising ocean levels will cause gigantic levels of havoc over the next decades, raising the risk of frequent floods, inundations and the possibility of being completely uninhabitable.

Florida, New York, and coastal California are among the most vulnerable in the U.S., according to statistics published by TIME in March 2016; Miami alone, policy-makers suggest, may already soon face the displacement of up to 2 million people because of global warming-induced floods and erosions. (Flooding as a result of rising sea levels is already very much a reality in the city.)

The rise in global sea temperatures worldwide has had a particularly devastating impact on the survival of coral, which is resilient only up to a point. And the real costs of the warming are showing up on one of the world's greatest natural wonders: Australia's Great Barrier Reef, off the coast of Queensland.

The devastation the warmer water, higher carbon dioxide levels, and increasingly extreme weather have created is becoming clearer: this year, the Reef saw its worst-ever coral die-off, with up to 67 percent of some areas transforming from living coral to bleached rock, as the organisms became unable to cope with the stress. Considering that you can see the Great Barrier Reef from space, and that it's the world's largest living structure with some 3,000 reefs across a gigantic area of 14 degrees of latitude, this is one of the biggest losses the natural world might ever see.

The erosion of coasts worldwide may have one of the biggest impacts on island nations like the Maldives, which was named as among the world's "most vulnerable" places in 2015 because of the devastating impacts of global sea levels. Beyond sea pollution, the rising sea levels have caused fears of displacement for many of the islands' inhabitants, as they, like several other island nations like Vanuatu, are only just above sea level. Current predictions indicate that, by 2100, rising ocean levels will inundate up to 77 percent or more of Maldives land levels. Residents are still trying to figure out other methods of survival, like expensive ocean walls.

Cambodia faces some of the most drastic changes as global warming shifts the planet's balances. A 2014 study of the countries that will suffer most from climate change, by American financial company Standard & Poors, ranked Cambodia as among the most potentially devastated, because of a combination of things: more than 10 percent of its population lives near to sea level, and agriculture — which is hugely vulnerable to changes in heat, rainfall, natural weather events, and other aspects of global warming — makes up a whopping 36 percent of its GDP. It's a recipe for disaster that will realistically mean that poor rural farmers without a livelihood become refugees in overtaxed cities, land mass reduces drastically, and the country's ability to support itself comes near collapse.

This is one of the biggest farming areas of the world, and it's already seeing significant changes through global warming. LiveScience noted in 2013 that a survey had found that up to 28,000 of China's rivers had disappeared since 1990, likely from both warming temperatures and industrial misuse. The country's rural center is already dry, and is becoming drier; like many of the farmers around the world, according to a study in 2014 by Christian Aid, Chinese rural agricultural workers will confront a landscape that is rapidly becoming unable to sustain them and their families, or to produce crops for export or use in the country's cities. Droughts are an increasing problem, and one day the land may simply be too poor to produce anything at all.

Like many low-lying cities worldwide, Mumbai in India is on the front line to receive serious damage as world water levels rise from the melting of the ice caps on the North and South Poles.

A 2015 study found that over 11 million people in Mumbai alone were at risk of losing their homes and livelihoods as the sea levels engulfed the coast, while 2007 predictions published in the Times Of India noted that global warming's inundations of coastal areas and destruction of rice yields could wipe out nine percent of India's GDP, with that figure only a rough approximation (it could get worse).

The idea of global warming isn't just confined to sea levels, of course. The other massive risk is the desertification of already-arid areas. Sudan has begun to experience this devastation first-hand as the Sahara Desert expands, though some scientists believe that desertification will be much more gradual and less abrupt than most current models predict (the Wall Street Journal in 2014 noted a study of ancient pollen records had found previous shifts in the Sahara from oasis to desert had been pretty slow).

However, the desert isn't the only threat. Erratic rainfall has caused huge pressure on farming communities and, experts note, fueled conflict and the civil war in South Sudan. Realistically, the way the world changes due to global warming won't just be because of natural shifts; it will be through how humans respond to new scarcities and dangers, from mass displacement of people to the difficulty of farming food or using land.

It's scary times we live in, so do your best to be an activist for the environment — or really, the humans who live on it. The earth will likely regenerate if we continue to make it inhospitable for human life; it will be humans who are really screwed in the long run.