“The new IPCC report,” tweeted Greta Thunberg, “... doesn't tell us what to do. It is up to us to be brave and take decisions based on the scientific evidence provided in these reports. We can still avoid the worst consequences, but not if we continue like today, and not without treating the crisis like a crisis.”

Boris Johnson has a different perspective. “We can’t just tear up contracts,” said the British prime minister, known across the world for shredding the Irish backstop. He was referring to the recently discovered Cambo oil field, west of Shetland, where oil companies Shell and Siccar Point Energy want to drill for at least 150 million barrels of oil, smashing through any hope of cutting carbon emissions by as much as is needed.

Because the field is technically attached to another, the oil firms assert their rights to it. Hence the contracts that ‘we’ apparently can’t just tear up.

The most important words in those two quotes are ‘us’ and ‘we’. Who are the ‘us’ who have to take these brave decisions? Who are the ‘we’ who can’t just tear up contracts, even when they mean turning the planet we inhabit into a tinderbox?

The report Thunberg is referring to, the new assessment of current climate science from the Intergovernmental Panel on Climate Change, makes me want to curl up and cry, to hold my baby daughter close and beg her forgiveness for our failures so far.

There’s that ‘our’ again.

“Global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered,” it says.

“Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in carbon dioxide (CO₂) and other greenhouse gas emissions occur in the coming decades.”

I was there, a dozen years ago, in Copenhagen, when governments negotiated over that difference between 1.5°C and 2°C – a difference that leaders of African and Pacific Island countries pointed out would likely define whether their whole countries remained habitable.

After we marched through the streets of the Danish capital, we knew we had failed. We were always going to. But twelve years later, we still need to understand that fact. Who is the ‘we’ who is willing to make these negotiations? Does it refer to all of us, or is it ultimately the royal ‘we’ of our rulers?

A few years before that conference in Copenhagen, my friends and I started to spot a trend. Politicians in Britain had stopped ignoring the significance of climate change and shifted, instead, to subtly deflecting blame. “Change your lightbulbs,” they told us. “Change the system,” we responded. But more people heard them than us. And fed up with being blamed, with being asked to carry the moral responsibility for existing in a system they did little to create, they harrumphed and did little.

Where individuals did pour their energy into reducing their personal carbon footprint, it made almost no difference. The rebound effect means that if one person uses less energy, then the price of energy falls, so someone else uses more. In January this year, New Scientist reported that any reduction in emissions from people buying electric cars was being cancelled out by other people buying SUVs.

And yet governments continue to try to say that the ‘us’ is all of us, that we must do our bit, that we must stop rinsing our plates before putting them in the dishwasher.

This, in a sense, is a form of climate change denial – the most pervasive form, the form that denies not the science, but responsibility.

There is another story about who that ‘us’ is. Looked at one way, just 100 companies are responsible for 71% of all emissions. Humanity has suspected the greenhouse effect for nearly 200 years and has known about the real dangers of climate change for decades. Yet decision-makers in a handful of businesses chose to continue down this runway, in order to ensure their profit margins took off.

The oil-reliant world in which we live has been built over the 75 years since the end of World War Two, and for most of that time, the science about what it would mean was clear to those doing the building. And yet they chose to keep going, knowing the risks. In this sense, blame is easily attributed, to specific people, with names and addresses – even if, as is increasingly the case, these details are hidden in documents filed in the secrecy of the Virgin Islands or Cayman Islands.

But surely this version of ‘us’ is also too bleak to simply accept? Surely we can’t just accept that our tomb has been sealed by some faceless plutocrat?

As Karl Marx once said: “[People] make their own history, but they do not make it as they please; they do not make it under self-selected circumstances, but under circumstances existing already, given and transmitted from the past.”

And, as he also said, “the tradition of all dead generations weighs like a nightmare on the brains of the living”.

But it’s up to us to shake ourselves from this nightmare. Because we can’t accept a world in which we leave whole countries to burn. And that means we must stop the government from allowing the oil under the seabed west of Shetland from being burned. Because we are not responsible as individual consumers. But we are responsible as citizens, as political actors, as people together. We do have the power to make our governments act like this is the crisis it is, because we must.