The Environmental Funders’ Network do a brilliant job of convening charitable trusts that provide support for green projects of one sort or another. When they asked me to write for their new blog, it was really interesting to reflect on the whole question of where their money could be spent. This is what I thought…. lots more interesting views on green funding on their blog.

A few years ago, I sat down to dinner with a group of enthusiastic young parliamentary candidates standing in the the 2010 election. In the company of climate scientists, policy experts and senior politicians, we talked about how to make climate change and low-carbon solutions central to their work in Parliament when (or if) they were elected.

Two thoughts were uppermost in my mind as I travelled home. The first was that we’d caught the candidates at just the right time. You could see that they were really thinking – they listened to what the scientists were saying to them, and they were thinking through how this would affect their lives and the lives of the constituents they hoped to represent. They were pleased to have the chance to try out ideas, and gain a bit of confidence in an area that they might not have considered before. I got the feeling that they might well come back to the issue. In short, it was a good investment.

But my second thought was this: to many, it might seem like a strange use of charitable funds to take a group of aspiring MPs to dinner. It’s a far cry from food banks or giving goats to families in developing countries – definitely not something you could shake a collecting tin for. Politicians don’t figure highly in most people’s list of worthy causes.

So why should we fund the politics?

Above all, because I think funding political change is an efficient use of money. If you get it right, the benefits are huge. Think of how important the Birds and Habitats Directives are to biodiversity in Europe. They are the result of good work by politicians, who have been given good advice by experts. Imagine how expensive it would be to protect those habitats without legislation (if, indeed it were possible) – through buying up land as reserves, or fighting every planning decision.

Likewise, policies to support renewable energy (currently under severe threat) have done a huge amount to cut carbon. They’re only there because of careful advocacy by green groups. In fact, the Climate Change Act itself, which sets long-term carbon targets, was the result of clever political work by environmentalists. Good political lobbying, resulting in good policies, has an amazing multiplier effect.

That’s not just true for the environment. Can anyone imagine a long-term solution to the current refugee crisis that doesn’t involve government action, in turn influenced by third sector advocacy? Sure, there will always be a need for direct support to individuals by charities and others, but funding political change can help get to the heart of the problem, not just the symptoms.

But if you agree that direct support isn’t enough, how about funding radical campaigns instead? Isn’t that the way to change things? Great campaigns can change people’s minds, raise media profile and encourage, or even force, politicians to act. I’ve lost count of the number of politicians who’ve spoken to me in admiring tones about the Jubilee 2000 Debt Relief campaign – an amazing collaboration between faith groups, development organisations and people from all walks of life, joining hands in a human chain round the Treasury to make a complicated international economic issue seem simple and solvable. And it worked.

But what you don’t hear so much about is the careful inside-track work that has to accompany any such campaign. Campaigns can say what’s wrong, and what needs to change, in simple slogans. They can create the political pressure for change – but they can’t offer detailed advice on what that change should be. High-profile campaigns need to be backed up by support, evidence and analysis to help politicians steer through the necessary changes. And yes, this might involve getting politicians round a dinner table.

My last reason might be one that’s better whispered than shouted. It’s this: politicians and policymakers aren’t always as clued up as they might appear. It’s hard to stay abreast of complex debates on, say, emissions trading or biodiversity legislation. A trusted advocate from an environmental group can give decision-makers the evidence and, indeed, the confidence to take a stand.

Back to that dinner. That was six years ago. And today I see some of the MPs who were round that table making the case for a low-carbon economy. Others have gone on to work with us to document how climate change is affecting their constituency right now. The investment we made will pay itself back through their parliamentary career. It’s not as direct or tangible as many charitable causes – but I’d argue it’s a strategy that reaps dividends. Even if you have to buy them dinner.