One of the specialty acts of a Superheroes has been dashing off to save some poor planet from destruction -sometimes even this one - but none as far as I know have become members of Friends of the Earth, Greenpeace. Rainforest Trust or any one of the many environmental organizations, or planted a tree or done their Superhero thing to confront some of the day to day threats presented by global warming.
This thought occurs because April 22nd is Earth Day.
The first Earth Day was on April 22, 1970, and is widely credited with launching the modern environmental movement. The passage of the Clean Air Act, Clean Water Act, Endangered Species Act in the USA were in large part due to their influence.*
The Earth Day Network has the mission to educate and activate the environmental movement worldwide.
Earth Day has been mocked for proposing one day a year to act on climate change but of course they don't. This is just one day used to draw attention to what is an all year round concern calling for all year round consideration.
The most common practice of celebration for Earth Day is to plant new trees.
*In March President Trump ordered his Cabinet to start demolishing a wide array of Obama-era policies on global warming — including emissions rules for power plants, limits on methane leaks, a moratorium on federal coal leasing, and the use of the social cost of carbon to guide government actions.