Climate change has not always commanded the attention it deserves, particularly in recent years. Two events this week have reminded us why we cannot afford to forget about it.

On Tuesday President Obama called for national and international action to tackle global warming.

Less than 24 hours after he finished speaking, the independent Committee on Climate Change warned [pdf] that the UK is not on track to meet its carbon reduction targets.

Their report highlights the grave threats but also the outstanding opportunities that combating climate change presents us with.

The case to act is both clear and compelling.

Our climate is changing. The causes are man-made. And we are already feeling the effects.

This shouldn’t be a matter of debate. The scientific consensus is overwhelming and includes 97 per cent of 4,000 academic studies carried out over the last 20 years.

As the President said himself on Tuesday, we don’t have time for a meeting of the Flat Earth Society.

He has listed Republican politicians who publicly deny climate change on his website. Judging by the noises that have been coming out of the Conservative Party over the past few weeks, we have enough material to start our own version here.

First the Energy Minister, Michael Fallon, dismissed climate change as “theology”.

Then Owen Paterson, the Environment Secretary, denied that the climate has changed – despite the twelve warmest years ever recorded all coming in the last fifteen. He added that any action to combat climate change may do more harm than good.

Elsewhere, Michael Gove is planning to airbrush climate change from the geography curriculum for key stage 3 students. And on the Tory backbenches, their ‘Alternative Queen’s Speech’ includes a bill to abolish the Department for Energy and Climate Change altogether.

Taken in isolation and any one of these examples would be cause for concern. Together, they paint a deeply disturbing picture.

What is even more alarming than what Tory ministers are saying, is what David Cameron is not saying.

At a time when world leaders such as Obama and President Hollande of France are speaking up about why we desperately need to seize this moment, our Prime Minister has apparently lost his voice when it comes to talking about climate change.

Remarkably, David Cameron hasn’t made a single speech on climate change in the three years since he became Prime Minister.

This is the same David Cameron who hugged huskies; said “Vote Blue, Go Green”; promised that his would be “the greenest government ever.”

But when you look at this Government’s appalling green record, it’s understandable why he is keeping quiet.

Our greenhouse gas emissions are going up rather than down: the UK’s carbon output jumped by 18 million tonnes in 2012 – more than any other country in Europe.

Investment in clean energy has plummeted to a seven-year low.

Less people are insulating their homes and the Green Deal, the Government’s flagship energy efficiency programme, isn’t working.

Now the government’s own independent advisors have warned that the UK has fallen behind on meeting our carbon reduction commitments.

It shows what a complete folly it was for the Government to ignore the Committee for Climate Change’s recommendation to set a decarbonisation target in the Energy Bill currently progressing through Parliament. Pledging to clean up our power supply by 2030 would provide a shot in the arm for our flat-lining economy and give the certainty to investors which they are crying out for.

The combination of anti-green rhetoric and inaction also weakens our hand when negotiating with other nations for a new global climate change agreement.

We are approaching the 2015 United Nations Climate Change Conference in Paris.

We need to take every opportunity to build support for an international climate treaty before then and the UK should be at the forefront of that effort.

Regrettably, the Prime Minister decided to omit climate change from the official agenda for the G8 leaders meeting in Northern Ireland. When I asked him about this last week, he said he didn’t see the point of having “a long conversation about climate change.”

Climate change isn’t something that we can wait to talk about next week, next month or next year. Only a few weeks ago the concentration of carbon dioxide levels in the atmosphere passed through the landmark threshold of 400 parts per million.

We have to act now. If we do there is a chance we can avoid a rise in global temperatures of above 2C – the level that scientists have deemed to be dangerous.

With the right strategy, commitment and ingenuity, we can create a new green economy in the UK and unlock massive job opportunities in the process.

Delay or hesitate and we risk being left behind by other countries more willing to face the future and catastrophic consequences for future generations.

It’s time the Prime Minister broke his silence and did something before it’s too late.