There can no longer be substantial doubt that human-made gases are the cause of
most observed warming.” The study also found that the ocean is slowly releasing this
stored heat, worsening the changes in climate already measured. Previously, skeptics
had claimed that the models that linked human emissions of carbon dioxide and other
GHGs to observed changes in the temperature of the world’s atmosphere could not
account for all of the warming that should be taking place if the connection between
human activity and climate change were as strong as some scientists claimed.14
Indeed, recent science has raised the concern that global
warming may be happening faster than the models predicted,
raising the threat that abrupt climate change could occur. This
increases the urgency of corporate and societal action.15
Many scientists now claim that to stabilize climate, the world will
need to reduce emissions of carbon and other GHGs 60-70
percent below current levels. The United Kingdom has already
pledged to implement such cuts and sees the economic
feasibility of doing so. California Governor Arnold
Schwarzenegger has called for that state to achieve an 80
percent reduction by 2050.16
The planet faces unprecedented perils. However, the answers
exist and are cost effective. The problem is that we have failed
so far to implement them.
Stabilizing atmospheric carbon dioxide levels will not be easy,
but it can be done. Using a combination of energy efficiency
and renewable energy, communities can shift from an economy
based on hydrocarbons to one running on carbohydrates. Such
technologies as far more efficient hybrid-electric cars and
efficient diesels using bio-diesel, wind machines, solar electric
and thermal collectors can enhance community prosperity,
reduce vulnerability and protect the environment. All of the
technologies exist to shift from coal and oil to much more benign sources of energy. In
his book, Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble,
Lester Brown describes a policy to cut carbon emissions in half by 2015.17 An analysis
by the German Environment Agency showed that World GHG emissions could be
halved by 2050 at a cost of just 1 percent of global gross domestic product. Without
action to restrain emissions, the cost of global warming-linked weather changes could
cut 10 percent of world GDP, it warned.