General Elections are rarely game-changers. The victories of Clement Attlee in 1945 and Margaret Thatcher in 1979 would arguably fall into that category, but most elections in my lifetime have been fought in the middle ground with party leaders jockeying to be the safest pair of hands.
Not this time. The advent of a seven-party contest means virtually everything is being questioned, from one angle or another, creating the possibility of a game changing outcome - for better or worse.
On no issue is this more the case than the threat of global warming. In 2008, when the Climate Change Act was passed, there was cross-party support in Parliament for the goal of reducing UK carbon emissions to 80% below the 1990 baseline by 2050.
That consensus is now being challenged not only by UKIP, which is calling for the Act to be repealed, but also by influential members of the Conservative Party such as Owen Paterson, the former Environment Secretary, and Lord Lawson, the Thatcher-era Chancellor of the Exchequer.
Lord Lawson’s think tank, the Global Warming Policy Foundation, argues that the science around climate change is “not settled” and opposes what it calls “economically damaging climate and energy policies”.
My own science education literally went up in smoke in school chemistry lessons long before the term global warming had entered mainstream political language.
Like many people, my choice largely has to be based on trust. So do I trust the synthesis of scientific opinion produced by the United Nations and the World Meteorological Organisation? Or do I wait to see if a small group of sceptics have a point?
For me, there is too much at stake to risk prevarication. If world opinion is right, we don’t have much time to save the planet from the mayhem caused by rising sea levels, severe droughts and exceptional storms.
And, in facing this historic choice, we have an opportunity to break, once and for all, from an economy based on finite fossil fuels that are mainly to be found either in inherently difficult locations (such as the shale under densely-populated areas of Britain) or in parts of the world where Britain has become deeply unpopular.
The man who chaired the last Government’s commission on climate change, Lord Stern, is calling on all countries to work towards making bigger commitments on carbon emissions at the next climate summit in Paris later this year.
He says the targets agreed by the EU, the US and China would still leave the world economy emitting quantities of carbon above the level needed to prevent global warming from having devastating consequences.
Meanwhile, Nobel laureate Desmond Tutu has starkly warned: “We can no longer continue feeding our addiction to fossil fuels as if there were no tomorrow. For there will be no tomorrow.”
In Wales, climate change is being taken very seriously. The business sector has brought its emissions down by 16.7% against the 1990 base line. Even bigger strides have been made in waste recycling where we are now ranked fourth in Europe and have decreased emissions by 20.4%.
But progress needs to be faster, especially in cutting carbon from road traffic, if we are to achieve even the current overall target of an 80% reduction by 2050.
The announcement last week that the Welsh Government intends to include statutory targets for reducing emissions in its Environment Bill signals a welcome sense of urgency.
“Climate change is perhaps the biggest long-term threat to our future generations,” said Carl Sargeant, the Minister for Natural Resources. “Including statutory targets will allow us to better evaluate progress, provide certainty to help drive investment for a low-carbon economy and confirm achievable targets to work towards.”
The choice facing Britain as a whole is whether to continue to tackle the threat of climate change or to follow the sceptics in chasing the idea that shale gas fracking will come to the rescue of a carbon hungry economy.
There is electoral arithmetic that could produce a Westminster coalition dominated by global warming deniers. That would indeed be a game changer – but to a highly dangerous game.
This is no time to play Russian roulette with our children’s lives.
Steve Howell is chief executive of Freshwater UK, the Cardiff-headquartered communications consultancy, and author of Over The Line, which can be ordered via www.steve-howell.com. Follow him on Twitter: @FromSteveHowell