Scientists and world governments have spoken:

climate change is unequivocal, its risks are real and our impact is clearer than ever.

The latest Intergovernmental Panel on Climate Change (IPCC) report launched is the most authoritative and comprehensive review of climate science available. It's been prepared by more than 800 scientists, cites more than 9000 papers and has been painstakingly approved, line-by-line, by 195 governments. The book of evidence is compelling.

Scientists are 95% certain that humans have caused the majority of climate change since the 1950s (up from 90% in 2007), a level often considered the gold standard for scientific certainty. They also have a far clearer picture of the toll climate change is already taking on our environment: sea level rise is accelerating; our oceans are acidifying; the rate of Arctic sea ice retreat has doubled; and glaciers and ice sheets are melting faster.

As the eminent economist Lord Stern reminded us last week, this stark analysis may even underestimate the risks because some messy, unpredictable factors have been left out of the climate models.

The risks posed by climate change are huge and governments need to manage them urgently. Scotland has been among the first nations to recognise and respond to the risks of climate change with its world-leading Climate Change Act, agreed unanimously by the Scottish Parliament in 2009. It has also been at the vanguard of the renewable energy revolution and is already meeting almost 40% of its electricity needs from renewables.

We are not alone in our approach, however. Weare part of a transition from fossil fuels to a cleaner energy future that is gaining and sustaining momentum. It is not just countries such as Denmark and Germany that are seizing the opportunity. Whilst China is the world's largest source of emissions, it is also a renewable energy powerhouse (the world's biggest investor) and is almost singlehandedly driving down the costs of solar energy technology. It is expected to accelerate its efforts to cut emissions over the coming years.

Scotland should be proud to be amongst the global leaders on this vital issue. Next week, the Scottish Government will host a conference on climate justice in Edinburgh, highlighting the unequal effects of climate change and our responsibility, as a developed nation with a massive climate debt, to protect those most vulnerable to its impacts. We must ensure Scotland delivers on its climate obligations, both legal and moral, before the window of opportunity closes.

Christiana Figueres, Executive Secretary of the UN Framework Convention on Climate Change, has described national climate laws as "the absolutely critical, essential, linchpin between action at the national level and international agreements". Credible efforts at home are central to securing the global deal the world so badly needs.

Scotland has already missed its first two annual targets under the Climate Change Act, so we need to go further, faster. In June, the Government set out an Action Plan to meet its climate goals.

It must be fully implemented and fully funded if we are to live up to our promises. Whether we will get a climate-proof budget remains unclear. The draft budget announced by the Cabinet Secretary in September provided encouraging signs on cycling support, but even this modest additional funding amounts to only a tiny fraction of the transport budget.

Crucially, the support for energy efficiency in the draft budget falls far short of what is needed to meet the Government's own climate and fuel poverty targets. We're calling on the Government to plug this shortfall and give the Scottish public the warm homes and affordable energy they need. We've recognised the risks of a warming world and we're poised to reap the rewards of the transition to a greener economy. But our efforts need to be more urgent and more far reaching to match the scale of the challenge ahead.