You could be forgiven for thinking this was the week Boris Johnson really grasped the perilous state of the planet.
After a long silence on environmental issues, he made not one but three “green” speeches to the UN biodiversity summit in New York.
At first sight, his promises looked ambitious: take the headline on a Downing Street press release which read “PM commits to protect 30% of UK land in boost for biodiversity".
Nearly a third of UK land protected for nature… that’s impressive, right? Well, not according to some.
Environmentalists called the press release a masterpiece of spin: it gave the impression that 30% of land would be protected for biological diversity.
But, as campaigners pointed out, the UK’s proposed protected area would mainly refer to land protected for beauty, not wildlife.
The “30 by 30” target was initially proposed by international green groups in 2018, and clearly referred to nature protection, not landscape value.
But much of the area to be included in the UK's proud 30% target are principally managed for walkers, tourists and sheep, not rare plants and insects.
In fact, some protected uplands are actually relatively poor in biodiversity, following decades of overgrazing.
This means the government’s only firm promise this week – after three prime ministerial speeches - is to safeguard just 4% more of the UK’s land for nature.
That’s hardly an urgent response to what the PM calls a crisis.
So what was the PM’s contribution to the summit?
Well, it pulsed with colour. He warned: “Consider the pangolin – that scaly mammalian miracle of evolution boasting a prehensile tongue that is somehow attached to its pelvis.
“I don’t believe any of us would choose to bequeath a planet on which such a wonderfully bizarre little creature is as unfamiliar to future generations as dinosaurs and dodos are to us today.”
But his scaly tribute bore no further new policies.
What about climate pledges?
The previous week, on the subject of climate change, the PM flamboyantly predicted that the UK could be the "Saudi Arabia" of wind power.
He declared himself an “evangelist” for the extremely expensive technology of CCS – carbon capture and storage, which buries CO2 in underground rocks.
He heralded a revolution for hydrogen fuel and said the UK would get more nuclear power. He also said Britain would phase out sales of new petrol cars earlier than planned.
But he didn’t say when, and didn’t give any details of other policies in his in-tray, or how they would be funded.
As the UK prepares to host next year’s world climate summit, the PM’s critics say he must urgently underpin his words with cash and timetables for delivery.
Former Tory minister Sir Nicholas Soames wrote in the Times that, despite recent rhetoric, the UK is falling behind on carbon-cutting generally and on the high-level diplomacy needed to unite international partners.
He said: “The government must wake up to the challenge in front of it and realise that the diplomatic landscape is the toughest it has been.”
So, what’s the PM doing right for the environment?
To be fair, the government is making pioneering moves in some areas of green policy.
It's committing to break the link between deforestation and UK supply chains. And it's helped lead the Global Ocean Alliance, which aims to protect at least 30% of the world’s oceans by 2030.
The UK’s Blue Belt programme is a little-publicised but major initiative on track to protect marine areas the size of India.
But real firm action is proving more elusive than words. Greenpeace was so incensed by what it called a lack of enforcement of marine zones that it dropped boulders in the North Sea to obstruct fishing.
On farming, the government also has - in theory - a good news story to tell.
It’s attracted admirers with its scheme to swap the widely-reviled EU farm policy for a grant system based on wildlife protection rather than farm size.
But now it seems the need to keep farmers in business may prompt ministers to raid the planned nature protection budget.
Meanwhile, the government's ambitious Environment Bill would enshrine biodiversity targets in law if only it wasn't stuck in the Commons for a want of Parliamentary time.
Does that mean the green promises are worthless?
The Guardian columnist George Monbiot offered a bleak assessment on the week's pronouncements.
“It’s the hope I can’t stand,” he said. “Every few years, governments gather to make solemn promises about the action they will take to defend the living world, then break them before the ink is dry.
“Wherever Johnson has been, a trail of broken promises litters his path like roadkill.”
Tony Juniper, head of Natural England, prefers to focus on potential. He told me: “If you look at it in the round, the government has an awful lot of good policies in the pipeline. If they manage to deliver their programme it’ll be a huge achievement.”
He said work was already under way to improve biodiversity in areas protected mainly for landscape value. If that succeeds, he said, it would make the 30% protection figure more impressive.
Mr Juniper’s guarded optimism was echoed by Julian Glover, who conducted last year’s government-funded review into National Parks.
He told me: “This is a rare chance to get reform, funding and more for nature and people.
“Environmentalists are right to point out today's big problems but I hope they will use this chance to get change and not just complain that because things for nature are often dire now there's no chance of a government helping make them better.
“It's good the PM wants to talk about the issue - let's encourage him to back action."
It’s rumoured that Mr Johnson was prompted to make the recent flurry of green announcements after being embarrassed by the reaction to his derogatory comments about rare newts in a speech on planning.
The big question now is what will nudge him to put finance and targets to the ideas in his green in tray?
Follow Roger on Twitter.