After completing his 7-mile trip to the bottom of the ocean floor, James Cameron, said he felt like he had gone to "another planet." And, in a sense, he had. Water pressure at the bottom of the Mariana Trench is so extreme that it's like "three SUVs resting on a toe." At such extreme pressures, life struggles to survive. Cameron, who saw only small-shrimp-like creatures in the water, said the ocean bottom resembled a "barren, desolate lunar plain."
But the Mariana Trench is not the only part of planet Earth that is feeling the pressure. That's why, half away around the world, nearly 3,000 scientists this week have assembled in London for a "Planet under Pressure" conference that is raising alarm bells about environmental conditions around the globe. And while those conditions may not approach those found at 7 miles beneath the ocean surface, they raise legitimate questions about prospects for life above and below the ocean waves.
Will Steffen, a climate expert at the Australian National University, warned the attendees that, "The last 50 years have without doubt seen the most rapid transformation of the human relationship with the natural world in history." He called this explosive growth in human activity "The Great Acceleration." Steffen said that Earth's climate was nearing several "tipping points" that could lead to a "much warmer" world when temperatures rise more than 2 degrees Celsius.
Steffen's was not alone in his dour assessment. Yvo de Boer, former executive secretary of the UN's Framework Convention on Climate Change (UNFCCC), said to reporters that, "I think 2 degrees is out of reach." Several other scientists at the London conference said that there was only a "50-50" chance of even limiting global warming to 3 degrees Celsius.
The "Planet under Pressure" conference may be one of the largest gatherings ever of scientists concerned about sustainability, but where is all this leading? Or as, Steffen so aptly put it, "Where on Earth are we going?"
The next stop, of course, is the Rio+20 "Earth Summit" being held in June. Hosted by the UN, the Rio conference will bring together political leaders, diplomats and scientists from around the world to discuss "sustainable development."
But the big unanswered question is whether, given population and consumption trajectories, "sustainable development" is becoming an oxymoron. So long as "more" is the goal, is there any combination of green technologies and better environmental practices that will lead us to a sustainable world? If world population climbs to 9.3 billion or higher by mid-century and global standards of livings rise on average by 3-4 percent a year, what does that mean for the world's environment?
Over the past century we've already wiped out 40 percent of the forests, 40 percent of grasslands and half of the world's wetlands. We've already collapsed most of the world's great fisheries, and boosted the rate of animal and plant extinction by a factor of a thousand.
What kind of pressure will the planet be under if the world's economic output at mid-century is four, five, or even six times higher than it is today? And what will that mean for climate change? Yes, we've been gradually de-linking GDP growth from growth in carbon emissions, but the de-linkage hasn't stopped greenhouse gas emissions from continuing to rise. Yes, the rate of population growth is slowing, but the latest estimates suggest that world population will not peak around mid-century, as many once previously hoped. And, yes, smarter management of critical bio-habitats could slow the rate of plant and animal extinction, but so far it has not.
If all we get out of the upcoming Rio conference is a pledge to work harder in promoting the adoption of green technologies, it will not fundamentally alter the human trajectory, and it will do little, if anything, to ward off an environmental day of reckoning.
Our only hope -- and it's a slim one -- is that policymakers and the public begin to recognize that a "planet under pressure" is the same thing as "humanity under pressure." We cannot continue to ruin the environment and expect that the environment will continue to support human aspirations.
When James Cameron looked at the barren ocean floor he may have thought that he was looking at "another planet," but, in fact, he may have been looking at what could happen to our own planet when the "pressure" becomes too great.