In previous years, these sled dogs in Northwest Greenland would be running on solid ice, even in June. (Steffen M. Olsen, Danish Meteorological Institute)

No matter where we were this past summer, one thing can probably be safely said: It was hot. Air conditioners worked overtime as heat waves hit the Midwest, Northeast and even Alaska in July.

We took the heat as another excuse to get out on the water for a cruise, to go fishing, to jump in a lake, to park ourselves under an umbrella at the beach or to hide in a dark, cool movie theater. We mopped our brows, ate more ice cream and drank more iced tea. Hot weather was the No. 1 topic of conversation.

We’ve all been through heat waves, but this time, most of us felt an underlying uneasiness, a nagging sense of disquiet. It’s getting a lot harder to deny that so-called weather anomalies are becoming more frequent and intense. They are far more common, but they’re not normal, and we know it.

Europe had a heat wave in June and a second heat wave in July. The latter one moved from Africa across the European continent and then stalled over Greenland, causing more than 11 billion tons of ice to melt in a 24-hour period, according to Martin Stendal, a climate scientist with the Danish Meteorological Institute, which has been tracking the ice melt since the 1970s. That level of melt had not been expected until 2070, according to Xavier Fettweis, a Belgian climate researcher at the University of Liège.

At the same time, the European Union’s Copernicus Atmosphere Monitoring Service, or CAMS, noted that parts of the Arctic Circle—in Greenland, Siberia and Alaska—broke out in unprecedented wildfires that masked major cities in heavy smoke.

If you still don’t believe in climate change, then your obstinacy in the face of facts is remarkable. (And that’s the polite way to put it.) The question is, can we do anything to halt this slide toward catastrophe?

You’ve probably seen the pigtailed activist Greta Thunberg. The 16-year-old went on a school strike last fall, sitting in front of the Swedish parliament building to draw attention to climate change. She sat alone, handing out homemade leaflets that contained climate facts and the statement “I am doing this because you adults are shitting on my future.”

Slowly, more people joined her and the media took notice. Less than a year later, she is the figurehead for a worldwide movement to force radical changes in response to the climate crisis. Her Asperger’s syndrome caused her to fixate on the issue with a sense of panic. This September, she was scheduled to attend United Nations climate summits in the United States and Chile. She won’t fly because of the impact planes have on the environment, but she caught a ride on Malizia II, a high-speed planing monohull built for the 2016-17 Vendée Globe race. Malizia II is fitted with solar panels and underwater turbines to generate zero-carbon electricity, so Thunberg’s trip will be emission-free.

Whether her actions result in real change will depend on all of us.

First, let your lawmakers know that you see the fate of our planet as an incredibly important issue. Write letters, sign petitions and speak up. The survival of our species is a nonpartisan issue.

Second, take small steps to limit your carbon footprint, reduce your reliance on fossil fuels and conserve our natural resources. No one expects you to hitch a transatlantic ride on a sailboat (though I’d love to) but do what you can. Take the train instead of flying or driving. Get a hybrid or electric car. Eat more local vegetables, fruits and grains, and less meat. Don’t waste food. Carry a reusable water bottle and a cloth shopping bag, and take every opportunity to turn away from plastic. Each small thing can have a much larger impact when thousands or millions of people do it.

Of course, we have not addressed the large fiberglass elephant in the room: Few of us own hybrid or electric boats, though builders are investing more in these technologies. Trawlers and other passagemakers are more environmentally friendly than many other types of boats, but we can’t kid ourselves that they’re anywhere near green.

I would never expect anyone to give up a boat. The point is, we can pick and choose. Doing something is always better than doing nothing. Our efforts don’t have to be perfect on every front—and we need to stay incentivized. I don’t know of anything more motivational than the beauty of a day at sea, the sun sparkling like diamonds across the cobalt surface, the smell of salt in the air, the sounds of gulls crying overhead.

Our watery world is so beautiful, and it’s the only one we have. Let’s not be blind or inert to the efforts it will take to save it.

This article originally appeared in the October 2019 issue.