Over the last year, two key concepts have reigned over all others: the economy and the environment. Like opposing forces they push and pull at one another, with economic downturns running counter to calls for increased spending on the environment, including renewable energy development and sustainability initiatives. And both problems are escalating, with the world's media reporting daily on the growing effects of climate change and the depression of the credit crunch. They are two all consuming and ever present problems; the environment because it represents the umbrella under which all human endeavour must operate - and indeed has originated from - and the economy because it is the system that we have chosen to dictate and moderate human endeavour, so that economics is the world's universal language, even if there are a few different dialects.

Like the great science and religion debates of the renaissance and enlightenment periods, the argument is certainly becoming polar; either one is an environmentalist or an economist; one is either for the environment and against economic growth - because our current paradigm links wealth to fossil fuels - or against environmentalism and for economic growth, because the credit crunch and the recession mean that money must be spent on trigger problems like housing, poverty, and world debt.

Can two such massive problems be reconciled? And can both be tackled, or must one be solved at the expense of the other? This is the contemporary political question. The environmentalist movement, in many respects a minority movement in previous decades, has - through a combination of committed activists and genuine causes - come, as it should be, to the forefront of politics. Indeed major political parties across the world have recognised the severity of the issue and have made it central to their policy and political spin. Many believe that the next round of the world's elections will be won or lost in part on the environmentalist performance of the leading contenders.

But the difficulty now is that an election will also be won or lost on economic performance because times are so tough. And the fear for environmentalists is that the current economic recession could spell a temporary sway in interest on the green issue; after gathering so much momentum, it could once again - though it might only be relatively short term - find itself on the fringes of the political agenda, because it has always been seen by the general public as an important and worthwhile discussion, but an essentially less pressing issue when viewed in combination with those problems with more immediate effects. And those, namely, are economic issues.

Certainly, the general view of environmental issues has changed for the better, and to some extent irrevocably. But an economic recession will almost definitely spell a decline, not in environmental discussion, but environmental action, because governments work in terms and not in decades; long term issues like the implementation of renewable energy, Kyoto protocol targets, or the switch to organic crop growth, will almost always fall foul of economic issues, which are often predicted in the long term but realised in the short term, and felt by almost everyone.

That is not to say that the environmental issue is a less important issue than the economic one. But the key now for environmentalists is to hold the ground that they have gained over the last 10 years, and to show just why global warming, CO2 emissions and climate change are still the most threatening problems on the planet, even if they are perhaps not the most pressing. And, despite the economic downturn, they must press, so that those issues becomes pressing. That way the environmental problem does not return to its former position as a sideline issue.

Indeed, it is a difficult task. But a necessary one.