'Now is the time for Scotland to lead the world with a 40% emissions cut'

How many genuine opportunities does Scotland get to lead the world? Not many. That's why, when we really have one, we must grasp it.

How many genuine opportunities does Scotland get to lead the world? Not many. That's why, when we really have one, we must grasp it.

This Wednesday's vote in the Scottish Parliament on the Climate Change Bill is one of those moments. By voting for a strong bill with a minimum of 40% emissions cuts by 2020, MSPs have the one and only chance to make this piece of legislation the best in the world.

But the vote on the bill hangs on a knife-edge, with parties battling over vital emissions targets.

The bill currently commits to cutting greenhouse gas emissions by only 34%, rising to 42% if European governments agree to reduce theirs at the international climate talks in Copenhagen in December.

Thirty-four-percent is far short of what the science demands if we are to avert dangerous climate change. And we can't wait until December to be led by Europe on a deal that might not happen. Scotland must act now.

We saw in the government's own climate change delivery plan last week that cuts of more than 40% are achievable for Scotland. We, the Stop Climate Chaos Scotland coalition, have shown them how it can be done. And in yesterday's Sunday Herald, eminent scientists from around the UK told them why it must be. The SNP committed to more than 40% in their own manifesto promises. So what's holding them back?

In the UK Climate Projections Study published last week, we learned how Scotland's weather will be affected by climate change by 2080: rising sea levels; more floods, storms and droughts. This is a worry for all of our futures.

However, climate change is not just an issue for future generations in Scotland, but for vulnerable people today who are already suffering its devastating effects. In Oxfam's work in over 70 countries, we are seeing first-hand the impact of climate change on people's lives, and the poorest - those least responsible for it and with the least resources to cope - are hit the worst.

Only recently, floods in Africa, Mexico and South Asia left 16 million people homeless. And Oxfam is predicting that in six years' time, the number of people affected by climate change crises will rise by 54% to 375 million people, threatening to overwhelm the humanitarian aid system.

So what's this got to do with us in Scotland? It's our emissions that are causing this chaos. Rich countries, like Scotland, produce three-quarters of the world's greenhouse gas emissions responsible for destructive climate change. Malawi, for example, whose people are struggling to cope with the impact of these emissions, produces less than 0.05%.

This week in parliament isn't a time for party politics or constitutional battles. It is about saving people's lives. Scotland has a great combination of natural resources and some of the world's leading experts in terms of technology and climate science to achieve this minimum 40% target.

Economically, it also adds up. Scotland has a remarkable store of largely untapped sustainable energy potential, providing opportunities for green-collar jobs and wealth creation to help tackle poverty at home and pull us out of economic crisis.

But ultimately, this Climate Change Bill is not just about science or economics. Fundamentally, it is about justice. Excessive carbon emissions are violating the rights of millions of the world's poorest people to life, security, food, health and shelter.

By voting for a strong target of at the very least 40%, MSPs from all parties, all of whom have had a stake in making this bill what it is, can ensure that Scotland lives up to its long-standing traditions of justice and fairness for all. Then we will have something truly world-leading that we can be proud of. But they must do it now, because after Wednesday, it'll be too late.