These before-and-after photos of rising seas might make you demand climate action.

1. St. Mark's Square in Venice, Italy

In Venice, the sea has always been close. After all, this is the city famed for its lovely canals and singing gondoliers paddling locals and tourists about. But after years of rising global temperatures, the water is rising, and engineers are finding it harder and harder to keep their beloved city above it. St. Mark's Square regularly finds itself calf-deep in seawater when high tides and full moons combine.Having floating seawalls and pumping groundwater out of city foundations helps hold back the rise — for now. But the city is sinking and sea levels are rising, and eventually one will prevail.

Here's what this public plaza looked like in 1955:

Photo by Hulton Archive/Getty Images.

And here's what it looked like a few weeks ago during Carnival.

Photo by Oliver Morin/Getty Images.

2. Shishmaref, Alaska

This tiny Alaskan village is located on a tiny island about 5 miles off the coast and 100 miles north of Nome. For the past 400 years, generations of Inupiat Eskimos have called it home. But as global temperatures rise and permafrost thaws, storm surges are quickly eroding the coast and undermining the town's homes, water system, and infrastructure.

Sea levels have been rising in Shishmaref for years. Here's what the community looked like in an aerial photo in 1998:

Image via Federal Aviation Administration, Alaskan Region/Wikimedia Commons.

This house once was waterfront. By 2006, the sea had claimed its foundation:

Photo by Gabriel Bouys/Getty Images.

3. The Rockaway Boardwalk in Queens, New York

After superstorm Sandy ripped the boardwalk from its foundations in October 2012, $140 million was invested in repairing it to its former glory. But as global temperatures rise, pumping more moisture into the atmosphere and fueling bigger, stronger storms, it's not a question of if another Sandy will happen but when.

Here's what the boardwalk looked like in August 2012:

Photo by Mario Tama/Getty Images.

And this is what was left of it in November 2012 after Superstorm Sandy roared ashore:

Photo by Spencer Platt/Getty Images.

4. Pacifica, California

Nestled alongside the ocean, Pacifica looks like a dream. But for the people living in the cliffside apartments and homes that dot the coast, it's a slow-moving nightmare. For years, strong storms (which compelling evidence suggests are fueled by man-made climate change) have eroded and undermined its picturesque cliffs, leaving some buildings a few feet from collapsing and others literally hanging in the air.

Here's a cliff-top home overlooking the Pacific just last year:

Image via Google Maps.

And here's a photo of the same home from another angle taken Jan. 27, 2016:

Note the patio hanging over the edge of the cliff. Image by Josh Edelson/Getty Images.

5. Miami Beach, Florida

At the Miami debates, Florida mayors begged presidential debate moderators to ask candidates about their views on climate change. It wasn't an unreasonable request. South Florida — Miami in particular — is viewed by climate scientists as one of the most likely places to disappear as sea levels rise a predicted 6 feet before the end of the century. First to go? Potentially Miami Beach, whose movie-ready boulevards are already flooding ankle deep when high tides and full moons combine.

Here's Miami Beach in 1935:

Photo via Hulton Archive/Getty Images.

And this is what happened in August 2015 when a high tide, a full moon, and rising sea levels combined:

Photo by Joe Raedle/Getty Images.

6. Grand Lahou, Cote d'Ivoire

The developing world — particularly in Africa's Sahel region—is already hard hit by our changing climate through extreme heat and unending drought. But its coastal regions are threatened, too. In Grand Lahou, a coastal village in Cote d'Ivoire, sea levels have encroached so far inland that they have washed rows of homes away.

Here is Grand Lahou's beachfront in 2007. Notice the tree in the center of the photo behind the house?

Photo by Issouf Sanago/Getty Images.

Here's a photo of that same beach — and same tree — taken just four years later in 2011:

Photo by Issouf Sanago/Getty Images.

It can be jarring to see just how quickly our world is changing from the effects of climate change.

But it's happening. Not 10 years from now. Not during our great grandchildren's generation. But right now in places we know and love. And if we don't get real about dealing with it, it'll only get worse.

Watching climate change transform our world can be paralyzing; it's hard to know what to do to stop a rising tide.

But there are people who can push forward the big changes that need to happen — and it's up to us to make sure they get there. The only thing that's going to drive the change we need is to push the people with power toward action.

And for some of them, the first step is seeing pictures like these that show what climate change might look like when it happens to them.