Most of the technologies that could reduce greenhouse gases are not only expensive but would need to be embraced on a global scale, scientists say. Many projections for 2030 include as many as 1 million wind turbines worldwide; enough solar panels to cover half of New Jersey, massive reforestation; a major retooling of the global auto industry; as many as 400 power plants fitted with pricey equipment to capture carbon dioxide and store it underground; and, most controversial, perhaps 350 new nuclear plants around the world.
