As everyone who was around the central Maine lakes this past winter and spring knows, they shed their ice blanket earlier than usual. That followed on the heels of a late ice-over and gave us the shortest period of ice cover in memory, at least on Salmon Lake, where I’ve kept records for the last 35 years.

The lake was iced over for just 67 days, a little over two months. This limited winter activities such as ice fishing and got the water warming much earlier in spring, enhancing the ability of ever-present algae to feed and multiply. For those of us who watch Salmon Lake’s water clarity decrease as the water heats up in July, that’s not good news.

The winter of 2023-24 was no anomaly. Climate change is beginning to have significant impact on the lakes. Summers are getting longer and winters shorter. Warmer lake water not only aids the growth of algae, it speeds all aquatic plant growth, including invasive plants such as Eurasian watermilfoil, which has taken root in nearby Cobbossee Lake and rendered parts of it unusable by swimmers and boaters.

At the same time, summer rainstorms are growing more intense and longer. Heat draws additional moisture into the atmosphere, making runoff problems greater and erosion worse, sometimes far back in the watershed where eroded soil washes into streams feeding the lakes. Those streams normally flow clear but turn brown with nutrient-laden soil during prolonged outbursts. Bigger storms raise lake water levels during high-wind conditions, leading to bank erosion and more phosphorus in the water. Phosphorus, found naturally in soil and added to fertilizers, is the primary nutrient feeding algae blooms.

We’ve known since the 1890s that burning these fuels adds gasses to the atmosphere that capture additional heat from the sun, like the glass of a greenhouse. The more gas we emit through combustion, the more effective the glass becomes at holding in heat, and the hotter we get.

The rise in temperature at the Earth’s surface started very slowly and made us complacent, but we’ve recently realized that the rate at which heat is increasing has accelerated. Every year now seems hotter than the last. In fact, the hottest ten years on record have all happened in the last decade. If you’ve been paying attention to the geophysical effects, as I have, it’s beginning to get scary.

At the start of the Industrial Revolution in 1780, there were about 280 parts per million of carbon dioxide in the atmosphere. That’s gone up to 427, and we’re adding about 4.5 ppm each year, a reckless pace, as recent prosperity in much of the world brings ever-greater energy consumption. The last time the atmosphere contained this much carbon was about 16 million years ago, when the temperature had already risen 12 degrees Fahrenheit because the process happened more slowly. Despite knowing this, we thunder on, careless of the consequences.

Tipping points, both known and unknown, await us. One just beginning, thawing the Arctic permafrost, will release vast quantities of the “greenhouse” gas methane, which is about 25 times more potent over 100 years than the carbon dioxide in combustion exhaust. More methane in the atmosphere will bring more heating, and a hotter Arctic will release more methane. That’s called “positive feedback,” but there’s nothing positive about it for Earth’s inhabitants.

A rapidly warming climate will make preserving our lakes as we’ve known them very difficult. It’s time for everyone who cares about lakes and streams, forests and wetlands – and the creatures who inhabit them, including us – to do everything we can to slow climate change and to protect those lakes, streams, and forests. You could say that our lives, and theirs, depend on it – whether it is individual actions, such as preventing erosion, joining environmental organizations, and installing solar panels, or it is supporting candidates who make environmental conservation a priority. Let’s go for both.