All signs suggest that the planet is still hurtling headlong toward climatic disaster. The US National Oceanographic and Atmospheric Administration has issued its "State of the Climate Report" covering January-May. The first five months of this year were the warmest since records began in 1880. May was the warmest month ever. Intense heat waves are currently hitting many parts of the world, yet still we fail to act.

There are several reasons for this, and we should understand them in order to break today's deadlock. First, the economic challenge of controlling human-induced climate change is truly complex. Anthropogenic climate change is caused by two principal sources of emissions of mainly carbon dioxide, methane, and nitrous oxide: fossil-fuel use for energy and agriculture (including deforestation to create new farmland and pastureland).

Changing the world's energy and agricultural systems is no small matter. It is not enough to just wave our hands and declare that climate change is an emergency. We need a practical strategy for overhauling two economic sectors that stand at the centre of the global economy and involve the entire world's population.

The second major challenge in addressing climate change is the complexity of the science itself. Today's understanding of earth's climate and the human-induced component of climate change is the result of extremely difficult scientific work involving many thousands of scientists in all parts of the world. This scientific understanding is incomplete, and there remain significant uncertainties about the precise magnitudes, timing, and dangers of climate change.

The general public naturally has a hard time grappling with this complexity and uncertainty, especially since the changes in climate are occurring over a timetable of decades and centuries, rather than months and years. Moreover, year-to-year and even decade-to-decade natural variations in climate are intermixed with human-induced climate change, making it even more difficult to target damaging behaviour.

This has given rise to a third problem in addressing climate change, which stems from a combination of the economic implications of the issue and the uncertainty that surrounds it. This is reflected in the brutal, destructive campaign against climate science by powerful vested interests and ideologues, apparently aimed at creating an atmosphere of ignorance and confusion.

The Wall Street Journal, for example, America's leading business newspaper, has run an aggressive editorial campaign against climate science for decades. The individuals involved in this campaign are not only scientifically uninformed, but show absolutely no interest in becoming better informed. They have turned down repeated offers by climate scientists to meet and conduct serious discussions about the issues.

Major oil companies and other big corporate interests are also playing this game, and have financed disreputable PR campaigns against climate science. Their general approach is to exaggerate the uncertainties of climate science and to leave the impression that climate scientists are engaged in some kind of conspiracy to frighten the public. It is an absurd charge, but absurd charges can gather public support if presented in a slick, well-funded format.

If we add up these three factors – the enormous economic challenge of reducing greenhouse gases, the complexity of climate science, and deliberate campaigns to confuse the public and discredit the science – we arrive at the fourth and overarching problem: US politicians' unwillingness or inability to formulate a sensible climate-change policy.

The US bears disproportionate responsibility for inaction on climate change, because it was long the world's largest emitter of greenhouse gases, until last year, when China overtook it. Even today, per capita US emissions are more than four times higher than China's. Yet, despite America's central role in global emissions, the US Senate has done nothing about climate change since ratifying the UN climate change treaty 16 years ago.

When Barack Obama was elected US president, there was hope for progress. Yet, while it is clear that Obama would like to move forward on the issue, so far he has pursued a failed strategy of negotiating with senators and key industries to try to forge an agreement. Yet the special interest groups have dominated the process, and Obama has failed to make any headway.

The Obama administration should have tried – and should still try – an alternative approach. Instead of negotiating with vested interests in the back rooms of the White House and Congress, the president should present a coherent plan to the American people. He should propose a sound strategy over the next 20 years for reducing America's dependence on fossil fuels, converting to electric vehicles, and expanding non-carbon energy sources such as solar and wind power. He could then present an estimated price tag for phasing in these changes over time, and demonstrate that the costs would be modest compared to the enormous benefits.

Strangely, despite being a candidate of change, Obama has not taken the approach of presenting real plans of action for change. His administration is trapped more and more in the paralysing grip of special-interest groups. Whether this is an intended outcome, so that Obama and his party can continue to mobilise large campaign contributions, or the result of poor decision-making is difficult to determine – and may reflect a bit of both.

What is clear is that we are courting disaster as a result. Nature doesn't care about our political machinations. And nature is telling us that our current economic model is dangerous and self-defeating. Unless we find some real global leadership in the next few years, we will learn that lesson in the hardest ways possible.

• Jeffrey D. Sachs is professor of economics and director of the Earth Institute at Columbia university. He is also pecial adviser to UN secretary-general on the millennium development goals. There is a podcast of this commentary.

Copyright: Project Syndicate, 2010.