What in the world will we do about climate change?

Today’s level of warming is manifestly unsafe. Each additional tenth of a degree doesn’t just displace another 100 million people; it also reshapes food systems, fisheries, and ecosystems on which billions depend. How many farms fail with each increment? How many fisheries collapse? At what point does shrugging off the challenge stop appearing to be realism and start becoming resignation?

Gary Rucinski

Massachusetts state coordinator

Citizens’ Climate Lobby

Newton

Ted Nordhaus is right that COP meetings are messy and inefficient. But his conclusion that the annual international climate conferences are useless or harmful rests on logical leaps that don’t hold.

First, the absence of a sharp cliff at 1.5 degrees Celsius doesn’t make the target meaningless. Climate risk is cumulative and probabilistic. The 1.5 degree goal functions as a coordination benchmark reflecting escalating risks to ecosystems, food systems, and vulnerable populations.

Second, declining disaster mortality doesn’t prove climate risk is overstated; rather, it shows that investments in early warning systems and infrastructure save lives. These gains won’t necessarily scale under continued warming, especially for countries with limited adaptive capacity.

Third, Nordhaus claims technological forces, not COP meetings, drive decarbonization. This ignores how international agreements have provided a level of policy certainty that helped justify massive investments in renewable energy. Solar and wind costs plummeted precisely because climate frameworks gave investors confidence to deploy capital at an unprecedented scale.

Finally, abolishing COP meetings without proposing a credible alternative for global coordination, finance, and accountability isn’t realism — it’s institutional abandonment at precisely the moment collective action is most needed.

Paul Swindlehurst

Londonderry, N.H.

The Jan. 11 edition of the Ideas section based its concerns about climate on increasing greenhouse gas levels. Of course, that is important. Unfortunately, other factors that many people are not thinking about may be more important.

When the phenomenon of the heat island was identified more than 200 years ago, it was limited to urban areas. We have largely ignored the impact of heat islands in the larger climate discussion because urban areas are relatively small as a proportion of total land mass.

While two of the five causes of heat islands — heat that is trapped between radiating building surfaces and restrictions to airflow — are limited to urban settings, the three primary causes — de-vegetation, bare ground and construction materials converting sunlight into heat, and thermal pollution — are now global phenomena.

Unless someone has repealed the laws of physics, these conditions are raising temperatures everywhere. Greenhouse gases serve as a pot lid. We need to stop turning up the stove.

Christopher Haines

Lexington

Congratulations for including a section on climate goals as an important topic for discussion, and to Roy Scranton for being the only writer to even mention the 8 billion people living on the planet, and their dependence on cheap energy from fossil fuels (“The world is getting hotter. Pessimism may be our only hope”).

Unfortunately, it seems people rarely mention the need for the human population to constrain itself in terms of numbers. In the face of climate change, how can we “stop it short,” as Bill McKibben suggests in the same edition, if we keep increasing the number of people on the planet? Maybe fusion power will become viable in the future, as Brian Bergstein argues, and wind and solar energy will prevail, as McKibben envisions, but really, why would anyone even want to live on a planet with as many as 12 billion people projected by 2100? Certainly not for the increased traffic, worse air and water quality, and crowded vacations.

In fact, the COP meetings are “a waste of time and resources,” as Ted Nordhaus writes, when it comes to real solutions; COP press releases, as far as I’ve seen, never even mention population as a factor in their calculations or suggest population stabilization. Governments and organizations refuse to acknowledge that overpopulation and consumption levels are indeed the elephant in the room.

Pessimism is not an environmental solution, but education just might be. If people learned more about the full impact of a human-centered world that values economic growth at all costs, they would gain a deeper understanding of the increasingly uncomfortable environmental effects they’ll have to live with. Then they might truly demand a wider range of solutions. A regular column in the Globe on basic ecology might make a big difference. The first installment might be a discussion of the essay “The Tragedy of the Commons” by Garrett Hardin.

Ira Dinnes

Marblehead