Oil executives and climate change activists alike want to curb the world's addiction to oil, but finding a realistic and effective solution is the challenge.

by Nina Easton, senior editor at large

FORTUNE - It's June 2050, and the Gulf Oil spill -- still ranking as America's biggest environmental disaster ever -- is four-decade-old news. If you were graduating college when BP's Deepwater Horizon rig exploded and sank, spewing a daily dose of tens of thousands of barrels of oil, you might now be celebrating your own kids' graduations. If your children were in elementary school at the time, you might be a grandparent by now. And if you were a grandparent in 2010...well.

The point is that 40 years is a long time for most of us. But it's not for energy planning -- and despite all the rosy talk that this disastrous spill will suddenly prompt America (or the world, for that matter) to ditch fossil fuels and plant a windmill on every neighborhood corner needs a reality check, one that was offered by a high-level panel at the Global Forum sponsored by Fortune, Time and CNN in Cape Town, South Africa this weekend.

Despite the spill, oil companies will continue to pursue deep water drilling. "The energy system will need all the energy being developed," said Royal Dutch Shell CEO Peter Voser. The reason: Over the next 40 years, the world's population will grow from 6.8 billion to 9.2 billion, and energy needs will double. More