We know the threat of climate disruption to Maine is real in part because we are experiencing early warning signs. The science is also clear that the problems will escalate if we do not act to further reduce carbon pollution.

There are now many important examples of how a warming climate threatens Maine, and here is one that strikes close to home for many Mainers: our changing marine environment could spell serious trouble for commercial fishing and all those who rely on it for a living. Consider the following:

• The Gulf of Maine is warming faster than 99 percent of world’s oceans.

• Maine’s shrimp fishery has been closed for several years now, attributed in part to warmer waters.

• Lobstermen and other fishermen are bringing up in new species from warming waters with their catch — presence of new species is not usually a good sign. For example, warming weather contributes to large increases in green crab populations, which ravages Maine clam flats and eelgrass beds.

• Clams and other shellfish face an existential threat: the same carbon pollution that is warming the globe is making ocean water more acidic and that makes it more and more difficult to build a shell.

These problems affect many Mainers, from commercial fishermen to all the households and businesses that they interact with. Commercial fishing is a $2 billion part of Maine’s economy, employing roughly 39,000 people.

We still have time to avoid broad scale impacts, and the solution is very clear: We must reduce the carbon pollution that is warming our land and seas and acidifying our oceans.

Maine has done a lot over the last 15 years to lead on climate and clean energy, but more needs to be done. Gov. Paul LePage recently joined other states in the region in setting a good achievable goal, consistent with science of reducing carbon pollution by 35 percent to 45 percent by 2030.

The question is: What are the most cost-effective ways to reduce this pollution? That’s where the Regional Greenhouse Gas Initiative (RGGI) comes in.

RGGI is the Northeast states’ market-based initiative to reduce carbon pollution from power plants, the No. 1 source of carbon pollution across the nation and region. RGGI sets a limit on carbon pollution and lets competition and market forces determine the best way to reduce pollution. Maine is part of RGGI, which has proven to be a great tool for doing our part to cut climate changing pollution, while boosting our economy and jobs and saving money, too.

Studies show that RGGI is one of our most successful climate polices. RGGI has reduced harmful carbon pollution while lowering energy costs and strengthening our overall economy. Since RGGI launched, member states have reduced emissions by 16 percent more than other states and seen 3.6 percent more economic growth. That’s something we should be proud of and build on.

One thing that makes RGGI so successful is that Maine uses most of our RGGI-generated funds to invest in energy efficiency improvements for homes and businesses.

Improving energy efficiency is one of the best ways to lower energy costs and pollution. RGGI funding has helped 10,000 homeowners add insulation or improve heating efficiency. RGGI funds have also helped many large facilities reduce energy costs — from paper mills to hospitals. For some businesses, savings on energy costs have made it possible to weather a recession or keep production in the state.

Another element of RGGI is the agreement between the states to review the program every three years to update and improve it, as needed. That review is happening now and offers important opportunities to make the most of RGGI’s success.

Because it is so cost-effective, and helps us lower energy costs, we believe RGGI should be the core part of meeting the region’s 2030 carbon pollution reduction target. At each stage, RGGI has proven more successful than expected.

We urge the Maine Department of Environmental Protection to continue to work with other states to set a long-term RGGI carbon cap that would help meet our overall carbon reduction goals and be in line with our rate of progress to date. Since tackling climate change also helps address other challenges Maine faces, such as growing the economy, making energy affordable, and creating jobs for the young people we want and need to inhabit Maine, we can and should find solutions like RGGI that advance multiple goals.

It’s good economic policy and the long-term livelihood of our marine economy depends on it.

George Lapointe is a marine fisheries and ocean policy consultant. He served as Maine’s commissioner of Marine Resources from 1998 to 2010. Tom Tietenberg is the Mitchell Family Professor of Economics, Emeritus at Colby College. His published research has focused on the design and evaluation of carbon-pricing programs (such as RGGI) around the world.