Exit Art For those of you concerned abut the planet (and seriously, that should mean you), Earth Day has now morphed into Earth week. (And hey, New York, shouldn’t it really be Earth Day every day?) In the city, museums and arts organizations have gotten into the act with installations designed to highlight the environmental issues facing the planet. PS 1 and The Museum of Modern Art took on the issue of rising sea levels, with the resulting “Rising Currents: Projects for New York’s Waterfront,” on display through October 11. (MoMA is at 11 West 53rd Street in Manhattan; 212 708-9400.) The creative solutions include water-absorbing sidewalks and apartment buildings that dangle above the water. (We said creative, not necessarily realistic.) The Brooklyn Children’s Museum (145 Brooklyn Avenue; 718-735-4400), which is being certified as the city’s first “green” museum, is offering the “Celebrate Earth!” Festival, a two-day, earth-focused extravaganza this weekend, April 24 and 25. An eco-fair and bark-painting workshop are among the offerings. Also in Brooklyn, the Waterfront Museum and Showboat Barge offers “A Thousand Thousand Slimy Things,” a play focused on the problems facing our oceans and ocean life. It’s offered through May 9 for older kids and adults. (290 Conover Street; 718- 624-4719). The museum promotes historical preservation and the city’s maritime past. Exit Art, (at 475 10th Avenue; 212 966-7745) is presenting “What Matters Most?”, through April 28. The exhibition was inspired by a "New York Times" blog that asked the question “What Matters Most?” Artists contributing to the exhibit either created works that related to a particular blog entry or presented relevant works. So take in an exhibit--and keep saving the planet.