Happy 49th Earth Day!!!

The big news for New York City co-ops and condos on Earth Day this year is that Mayor Bill de Blasio is signing the most ambitious climate law in the world, with the goal of sharply reducing carbon emissions from the city’s worst polluters, its buildings. The ramifications for co-op and condo boards are immense, and we’ll be covering the story as it unfolds in the coming months and years. 

Meanwhile, there’s a full roster of events to help New Yorkers celebrate a day devoted to our embattled planet. Here, compiled by amNewYork, are a few: 

Take an urban ecology cruise. Circumnavigate Manhattan while a guide from the American Institute of Architects, New York chapter, teaches you about New York Harbor’s estuary and ecological diversity on this Classic Harbor Line tour, which includes hors d’oeuvres and a beverage. Monday, 1:45-4:30 p.m., $96/adults, $78/students and ages 14 and up; Chelsea Piers, Pier 62 (West 22nd Street), sail-nyc.com 

Go on the Earth Day 5K Green Tour. Explore green sites around the city on this tour, stopping at a rooftop farm, a river ecology school on the Hudson River, a zero-waste office and more. Tours run about three to four hours and include lunch from Just Salad. Monday, various start times, $30-$50; earthday5k2019.eventbrite.com 

Get hands-on at the Museum of the City of New York. Bring your family to the Museum of the City of New York for a scavenger hunt in the exhibit "Activist New York," flower planting and a papermaking workshop. Monday, 11 a.m.-2 p.m., admission $18/adults, FREE 19 and under; 1220 Fifth Ave., mcny.org

Make art at the NYBG. Create your own art projects using recycled materials at the New York Botanical Garden activity, "One Person's Trash Is Another's Art!" Monday, noon-4 p.m., All Garden Pass $23/adults, $10/ages 2-12; 2900 Southern Blvd., Bronx, nybg.org