One man has come up with a solution: the Finlander Pentii Linkola. Excerpt here.

Humanflood

By Pentti Linkola
Translated by Harri Heinonen and Michael Moynihan
Introduction by Michael Moynihan.
Is Pentti Linkola posing the most dangerous thoughts mankind has ever considered? Or is he this planet's only remaining voice of sanity? Living an ascetic existence as a fisherman in a remote rural region of his frigid homeland, the Finnish philosopher has pondered mankind's position vis-?-vis the earth it inhabits and dares to utter the unspeakable. In order for the planet to continue living, man - or homo destructivus, as Linkola names him - must be violently thinned to a mere fraction of his current global population. Linkola's metaphor for the predicament is as follows:
What to do, when a ship carrying a hundred passengers suddenly capsizes and only one lifeboat, with room for only ten people, has been launched? When the lifeboat is full, those who hate life will try to load it with more people and sink the lot. Those who love and respect life will take the ship's axe and sever the extra hands that cling to the sides of the boat.
As time creaks onward, Linkola's predictions and indictments grow more dire. He has come to realise that extreme situations demand extreme solutions:
"We still have a chance to be cruel. But if we are not cruel today, all is lost." The sworn enemy of Christians and Humanists both, Linkola knows that the fate of the earth will never be rescued by those who exalt "tenderness, love and dandelion garlands." Neither the developed nor under-developed populations of the planet deserve to survive at the expense of the biosphere as a whole. Linkola has urged that millions will starve to death or be promptly slaughtered in genocidal civil wars. Mandatory abortions should be carried out for any female who has more than two offspring. The only countries capable of initiating such draconian measures are those of the West, yet ironically they are the ones most hamstrung by debilitating notions of liberal humanism. As Linkola explains, "The United States symbolises the worst ideologies in the world: growth and freedom." The realistic solution will be found in the implementation of an eco-fascist regime where brutal battalions of "green police," having freed their consciences from the "syrup ethics," are capable of doing whatever is necessary.

Full article here.