Of course, we would still need to deal with the national security risks of our growing dependence on a global oil market dominated by dwindling reserves in the most unstable region of the world, and the economic risks of sending hundreds of billions of dollars a year overseas in return for that oil. And we would still trail China in the race to develop smart grids, fast trains, solar power, wind, geothermal and other renewable sources of energy - the most important sources of new jobs in the 21st century.

But what a burden would be lifted! We would no longer have to worry that our grandchildren would one day look back on us as a criminal generation that had selfishly and blithely ignored warnings that their fate was in our hands. We could instead celebrate the naysayers who had doggedly persisted in proving that every major National Academy of Sciences report on climate change had simply made a huge mistake.

I, for one, genuinely wish that the climate crisis were an illusion. But unfortunately, the reality of the danger we are courting has not been changed by the discovery of at least two mistakes in the thousands of pages of careful scientific work over the last 22 years by the Intergovernmental Panel on Climate Change. In fact, the crisis is still growing because we are continuing to dump 90 million tons of global-warming pollution every 24 hours into the atmosphere - as if it were an open sewer.

Flawed estimate

It is true that the climate panel published a flawed overestimate of the melting rate of debris-covered glaciers in the Himalayas, and used information about the Netherlands provided to it by the government, which was later found to be partly inaccurate. In addition, e-mail messages stolen from the University of East Anglia in Britain showed that scientists besieged by an onslaught of hostile, make-work demands from climate skeptics may not have adequately followed the requirements of the British freedom of information law.

But the scientific enterprise will never be free of mistakes. What is important is that the consensus on global warming remains unchanged. It is also worth noting that the panel’s scientists probably underestimated the range of sea-level rise in this century.

Here is what scientists have found is happening to our climate: man-made global-warming pollution traps heat from the sun and increases atmospheric temperatures. These pollutants have been increasing with the growth in the burning of coal, oil, natural gas and forests, and temperatures have increased over the same period. Almost all of the ice-covered regions of the Earth are melting. Hurricanes are predicted to grow stronger and more destructive, though their number is expected to decrease.

Droughts are getting longer and deeper in many mid-continent regions, even as the severity of flooding increases. The seasonal predictability of rainfall and temperatures is being disrupted, posing serious threats to agriculture. The rate of species extinction is accelerating to dangerous levels. And in spite of President Obama’s efforts at the Copenhagen climate summit meeting in December, global leaders failed to muster anything more than a decision to “take note” of an intention to act.

This comes with painful costs. China, now the world’s largest and fastest-growing source of global-warming pollution, had privately signalled early last year that if the US passed meaningful legislation, it would join in serious efforts to produce an effective treaty. When the Senate failed to follow the lead of the House of Representatives, forcing the president to go to Copenhagen without a new law in hand, the Chinese balked. With the two largest polluters refusing to act, the world community was paralysed.

New approach

We should have no illusions about the difficulty and the time needed to convince the rest of the world to adopt a completely new approach. The lags in the global climate system, including the buildup of heat in the oceans from which it is slowly reintroduced into the atmosphere, means that we can create conditions that make large and destructive consequences inevitable long before their awful manifestations become apparent: the displacement of hundreds of millions of climate refugees, civil unrest, chaos and the collapse of governance in many developing countries, large-scale crop failures and the spread of deadly diseases.

It’s important to point out that the United States is not alone in its inaction. Global political paralysis has thus far stymied work not only on climate, but on trade and other pressing issues.

The reasons for this are primarily economic. The globalisation of the economy, coupled with the outsourcing of jobs from industrial countries, has simultaneously heightened fears of further job losses in the industrial world and encouraged rising expectations in emerging economies. The result? Heightened opposition, in both the industrial and developing worlds, to any constraints on the use of carbon-based fuels, which remain our principal source of energy.

From the standpoint of governance, what is at stake is our ability to use the rule of law as an instrument of human redemption. After all has been said and so little done, the truth about the climate crisis — inconvenient as ever — must still be faced. The pathway to success is still open, though it tracks the outer boundary of what we are capable of doing. It begins with a choice by the United States to pass a law establishing a cost for global warming pollution.

We have overcome existential threats before. Winston Churchill is widely quoted as having said, “Sometimes doing your best is not good enough. Sometimes, you must do what is required.” Now is that time. Public officials must rise to this challenge by doing what is required; and the public must demand that they do so — or must replace them.