The struggle for action against climate change is one Lib Dems have played their part in, with a proud environmentalist tradition that has only got stronger in recent years. In arguing that climate change science is compelling, we are happy to make common cause with people from any other political stripe. To demonstrate the problem, that’s quite proper. There are still climate-change deniers (usually funded by Exxon-Mobil) and dismissing their propaganda is vital.

However, once we accept that climate change is real – and scarier for the fact we have so little certainty about what that means – there’s an entirely new debate on what should be done in response. I think we’re on the cusp of that debate, and we should begin to prepare for it. While the Green party tout a more authoritarian approach, which sees liberal capitalist democracy as the cause of the problem, I think a liberalism attempting to green modern life will be more palatable than fundamentally reorganising society.That doesn’t mean that a green liberalism is a soft option, or that it doesn’t mean dramatic changes in human behaviour. But it means that rather than using state force directly to prosecute individuals for every minor infraction, we can use the tax system to correct for the failure of the market to consider the impact of carbon emissions and other pollutants. Not only do I believe this will be a more palatable way of tackling climate change, but I think it’s the only realistic option of carrying popular support. It is actually a tragedy that a big-G Green approach is commonly mistaken as typical of all environmentalism: bossy, intrusive, and interested in hair-shirtism. There’s another way, which our Green Tax Switch already points to.

The big debate that’s coming is, therefore, who has the best solutions on climate change. That’s a fight we should gear up for. While our new green taxes have been sold as evidence we’re deadly serious about climate change – and rightly praised by Greenpeace as ‘the gold standard’ – they are also the opening salvo in that second debate. There is some way to go before we can move from ‘why this matters’ to ‘why we’ve got the best answers’, but we should be ready for that debate, because getting the right solutions (and ones that are realistic and saleable to the public) will be as important as proving the need for action on climate change in the first place.

That’s why I’m delighted by a new educational game about climate change, that the BBC will be using in the next month to follow up their collaboration with www.climateprediction.net. It’s been built by Red Redemption, based here in Oxford, and was designed for 25-35 professionals, although I suspect it will find a far wider audience. The almost-finalised version I played this week confirms what a brilliant tool for answering both questions: why and how.

The premise of the game is to offer you, as the President in charge of a united Europe, various options on everything from trade to energy generation to the retirement age to regulating households. The decisions made impact energy, food, water and economic production, as well as carbon emissions. Hence, the trick is – just as in real life – to meet emission targets whilst meeting the demands of living and keeping popular approval.

A game like that is only as good as the modelling behind it, and while I’m sure there will be grumbling (“carbon allowances would be much less popular than that”) the general outline is compelling – and should be given the science and policy side was provided by Oxford University’s  Environmental Change Institute. Far meatier than anything I’ve seen before (I took 40 minutes to play through a game), this is a tool that will kick-start a lot of thinking on the different ways of meeting the necessary reductions in carbon emissions.

One key message it supports, is that the West needs to lead the way in demonstrating and developing low-carbon living. While the game focuses on Europe, the emissions of the other continents of the world are considered, and a player has to convince them to accept emission caps too; a process that relies on them seeing commitment from you. Most importantly of all, new technologies born in the developed world can potentially allow the developing world to skip levels of industrialisation, and ensure their own modernisation doesn’t have the destructive externalities ours did.

The game, Climate Challenge, will hopefully pick up a lot of attention when it laucnhes (they’re hoping within a fortnight), partly for its demonstration of the climate impact of policy decisions, but also for showing the variety of different routes available to us. A version for students as Key Stages 3 and 4 is already in the works, so the use of new media (as well as Al Gore’s powerpoint presentation) in raising these issues will continue unabated.

That’s a good thing, as it spurs people to thinking what they can do in their own lives and – crucially – what sort of national solutions they believe can best combine effectiveness and realism. The first climate challenge is starting to be won (although not before time), as Britain wakes up to the need for action. But that second climate challenge, in finding a convincing set of policies to deliver it, is just about to begin. For our part, that means producing and selling green liberalism, in contrast to the green illiberalism often passed off as the only form of environmentalism. It’s not just important for the civil liberty implications; it’s also the only package that’s both serious and viable. Joe Otten and I are hoping to drag together contributors for a book describing what that might look like, so if you’d like to get involved, please drop me an e-mail.