We like to think of climate change as a future event, something that hasn’t quite hit yet, that we can still stop when we decide to set our minds to it. This isn’t the case.

The planet’s already experiencing irreversible effects of climate change. While some of the hardest-impacted places are poor and remote — like the Pacific Islands swallowed by the sea, or the villages of Darfur torn by climate-influenced conflicts — others are much more prominent to us Westerners. Natural wonders, major cities, and cultural icons are all at risk. Here are just three examples, permanently transformed by climate change.

New Orleans

It’s been nearly a decade since Hurricane Katrina hit New Orleans, and there are still areas, like the devastated Lower Ninth Ward, that aren’t close to fully recovering. Yes, the city’s full of incredible, resilient people — and that much will never change — but it’ll likely bear the scars of Katrina forever. And it remains vulnerable to future storms.

It’s impossible to confirm that Hurricane Katrina was caused by climate change, of course. Catastrophic hurricanes have been happening since long before humans started influencing their environments. But, since warm ocean waters are fuel for hurricanes and typhoons, the warming climate is expected to increase the frequency and intensity of such storms by supplying conditions conducive to their formation.

Storms of the century may become more like storms of the decade. In the US alone, with Katrina and Sandy, we’ve already had two abnormally catastrophic storms in the past ten years. New Orleans and other coastal towns will continue to be susceptible to storms and floods from now on.

The Great Barrier Reef

Not all the carbon dioxide we release into the atmosphere stays in the atmosphere. About a third of it’s absorbed by the oceans. When carbon dioxide ends up in the sea, it acidifies the water, which detrimentally affects the shells and skeletons of ocean creatures — including coral — in a process called “bleaching.”

Coral reefs are one of the most biologically diverse and important types of ecosystems in our oceans, and we depend on them heavily as fishing grounds for the seafood industry. They also help protect our shorelines, serving as a barrier to rougher seas and their erosive forces. Bleaching is a symptom of corals becoming weaker, and as reefs die, the ecosystems built up around them die too.

Not even the world’s biggest reef — the Great Barrier Reef off the coast of Australia — is immune. According to a UN Intergovernmental Panel on Climate Change (IPCC) forecast, “by 2050, 97 percent of the Great Barrier Reef will be bleaching yearly.” In other words, the reef will be dying. Not only is this a disaster from an ecological point of view, but less reef means less seafood on our plates and lost revenue from tourism and recreation.

Glacier National Park

While Montana’s Glacier National Park is hardly the only or the worst example of glacial melt, as one of the crown jewels in the US national park system, it’s perhaps the most conspicuous. It’s named Glacier National Park, after all. The park is beautiful with or without the glaciers, but when it was founded about 100 years ago, there were 150 glaciers within its borders. Now there are 25. By one estimate, they’ll all be gone by 2030.

The loss of glaciers isn’t anything new in terms of geologic history — icesheets advance and retreat every 40,000 to 100,000 years. But anytime someone cites this fact as a reason for regulatory inaction, gently remind them that a) we caused this and can stop it and b) if we don’t, there will consequences.

Not only do hundreds of millions around the world rely on glaciers as a water source, but roughly one in ten humans lives on a coast that could be affected by sea-level rise.

Compared to the icesheets of Greenland or Antarctica, Glacier National Park is small beans, but it’s a horrifying example of foreshadowing.