At the Jackie Robinson Playground in Crown Heights, the trees provide shade and some relief from the summer sun. But the park may have some unwanted shade if two mega-developments go up across the street.

The proposed projects would also cast shadows over the 108-year-old Brooklyn Botanic Garden, and its renowned plants and flowers.

"We now have a shadow study, and that shadow study told us if two of these proposed projects are actually done, there will be 17.3 acres of shadows cast on the gardens," says Brooklyn resident Alicia Boyd.

Boyd is with the Movement to Protect the People. The group commissioned a shadow study to help fight the developments. Under current zoning, buildings here can be no higher than seven stories. But Cornell Realty wants to build a 22-story project, and the Continuum Company wants to erect a 42-story tower.

"We are demanding that the project be done according to the 6-7 story height limited zone," Boyd says.

The shadow studies present simulations showing how the sun would be blocked at different times of the day throughout the year. Scalar Architecture and the Terreform Center for Urban Research prepared them for the city's public review of the proposed rezonings.

"You do the shadow study for four dates, the fall and spring equinox and the winter and summer solstice, because this provides a full spectrum of shadows that will be cast throughout the year," says Terreform Research Director Andrea Johnson.

"These shadows are going to impact the entire neighborhood quite significantly. People's homes, people's courtyards, people's gardens," says Julio Salcedo of Scalar Architecture.

Boyd points out that the shadows created by the developments will reach as far as Prospect Park.

Over at the Rockwell Place Bears Community Garden on Flatbush Avenue, another anti-development campaign is taking place.

SOS, Save Our Sunlight, is fighting a 74-story tower proposed for 80 Flatbush Avenue in Downtown Brooklyn.

SOS also commissioned a shadow study. Columbia University Professor David Eisenbach, a candidate for public advocate, says these fights are becoming more common as developers reach ever higher.

"We as New Yorkers have to embrace this fight. From all over the city, not just from Brooklyn," Eisenbach says.

Eisenbach and other opponents of these mega-projects say city planners must consider the cumulative effect of all the new development, a city increasingly in the shadows.