There is no backlash against the Millennium Development Goals; there is no throwing up of hands. In a very cynical age, the UN draft declaration is a cynicism-free document. Important things can be done. And the goals that we set are practical and effective.

The main thing we have learned in the last 10 years is how practical it is to help farmers to grow food; how effective it is to build more schools, to build more clinics, to make sure people sleep under anti-malarial bed nets – to actually do things. We've also learned that rich countries are perfectly able to make promises they don't follow through on and then say that we were wrong all along.

Compare the spending on development to the spending on war. We have shown we can control malaria and Aids globally but if we're spending on wars we won't be able to do that.

There are armchair academics who champion cynicism and there are those of us actually doing things and showing that it's doable.

Development is hard, but it isn't as hard as getting the US, France, Germany, Great Britain to honour their commitments. Don't ask me why the promises haven't been kept. Go and ask the treasuries; go and ask the German finance ministry. We had a commitment to move to 0.7 per cent of rich world spending on overseas development assistance. We had a commitment to US$23 bn on agriculture (in Africa) – but the fund is empty. Aid is at 0.34 per cent, roughly half of the promise. These amounts are equivalent to a couple of days of US military spending. This is not a question of capacity; it's about how governments organise themselves.

I don't see the other arguments frankly. It's chit chat in rich countries. When you get on the ground in poor places you see that aid is necessary and life changing. The issue isn't to abandon the goals, the problem is the follow through.

What we need is multi-donor funds that really work. The Global Fund for HIV/Aids is the best example of that. Every so often something like the Global Fund comes along and it works – instead of fights over budgets which, in US budgetary terms and in my view, are a rounding error. The UK is the leading example where politics and public interest has pushed politicians to do the right thing – the same is true in the Netherlands and in Scandinavia. The real challenge is scaling up.

Eight global goals were set up and we have established a track record of progress but not on the trajectory that was called for, and not at the necessary scale.

This week 10 years of goals will be reaffirmed in a sensible way. The unmet part of the week is the "how".

We should have one global fund for education, one for infrastructure, one for adaptation and mitigation of climate change, and so on. And they should all fully capitalised. Then we should invite countries in a serious way to come forward with a plan of action and have aid programmes agreed as contracts.

Jeffrey Sachs is head of the Columbia University Earth Institute