Science produces many new theories of which new materials or methods could revolutionise the world. Some of which contribute to a more eco-stable environment.
But the most pressing concern these days is the relentless need for fossil fuel. In 2050, the expected need for oil will double, taking into account that most cars will use less fuel. But what alternatives do we have? Wind turbines are too cost intensive, expensive and require maintenance, solar power depend on the sun and are expensive. But what about nuclear. This pollutes right?
Does nuclear power pollute, yes. However in a nuclear waste reprocessor you don't use refined uranium. You use radioactive waste as the fuel. In principle extending the lifetime of the current uranium by a factor of 19. In stead of the 5% efficiency that regular nuclear power plants can generate, this type gives a whopping 95% efficiency. 
This has many advantages; Less radioactive waste, and less radioactivity. 1800% more power output, no extra mining for uranium, no extra refining, and you can actually use the stockpiled waste as fuel.
In the end, uranium is a fossil fuel, however there is a lot to win in this matter. Using this method, the world could be powered solely by nuclear power. This is something we have to look into.
Transferring mechanical energy from point A to B has been done the same for thousands of years. This proces is relatively inefficient and ready for an upgrade. The whole system of rotating rods and gears is high maintenance, expensive, unreliable and affected by temperature, moisture and takes up precious energy. This energy is then used to heat up the system, or to chip away on the gears.
So a way to minimize energy loss on a system like this would be a great asset to efficiency, and thus ecology. Magnets that can be programmed to perform as any type of gear are the solution. With it, there will no longer be scraping of gears in your cars gearbox, no longer you will visit a watchmaker and the trip with the car will be about 5% more efficient. 
Magnetic bearings, gears and engines may be the future, but for some cases they will simply be inadequate. Structurally, magnets simply don't offer the same strength as steel, or titanium. First they will be used for high speed gears, like in cars, but in a crane this would exceed the capability of most magnets. Secondly, they would be used in precision hardware.