When Keir Starmer arrives in Liverpool this weekend promising an upbeat tone to Labour’s first conference in power for 15 years, he will boast of his party’s strong start to its first 82 days in government.

In just the last two months, the new government has made more green reforms than Rishi Sunak did in his entire premiership and Labour has plenty to celebrate: it has taken the first steps to crack down on water companies and clean up our filthy rivers; stopping oil and gas licences, and withdrawing support for a new coalmine; setting up a new renewable company, Great British Energy; a green light for new on and offshore windfarms; and an international charm offensive to signal renewed UK leadership in climate and nature diplomacy; alongside a host of smaller changes.

But when the prime minister stands up to speak, the squads of green policy experts and green businesses and investors who are set to gather in Liverpool will be listening carefully for his emphasis.

For net zero to succeed, Starmer must make it a core priority for Downing Street and Whitehall. So far, the flurry of green-tinged policy activity has centred on two core departments, the revamped Department for Energy Security and Net Zero led by, Ed Milibandand the Department for Environment and Rural Affairs led by Steve Reed.

This week, the foreign secretary, David Lammy, also joined in, vowing before an audience of diplomats from around the world to make the climate and nature “central to all the Foreign Office does”.

What has been missing so far are clear plans from the rest of the government to make their own contributions to net zero. From transport – the biggest source of greenhouse gas emissions – to industry and housing, reaching net zero will depend heavily on departments that do not have “net zero” in their title.

Department for Transport

Emissions from transport have remained stubbornly high for more than a decade,and experts say more radical solutions are needed than just mandating that new car sales must be electric by 2030, a target that has already been watered down to allow hybrid petrol/electric vehicles to count.

Labour has made a start on this, with the renationalisation of the railways a core manifesto promise. Bus routes will also be revived, under new legislation to allow local authorities to take back control of them.

But Reeves has cancelled infrastructure projects in her quest to shave billions from government spending and there is no programme to revive the northern leg of HS2.

Perhaps more significantly, airport expansion also falls under the DfT’s remit. London’s Heathrow, Gatwick and City airports, as well as several others across the country, including Luton, Bristol, Manchester and Birmingham, are pleading for expansion. That cannot happen without correspondingly large emissions cuts elsewhere, the Climate Change Committee has said. Yet Reeves has repeatedly mentioned airport expansion recently as a way to foster economic growth.

Verdict: It will take more than Louise Haigh on a bike to make the massive emissions cuts needed from transport – tough decisions on air, rail and SUVs cannot be avoided for long.

Ministry of Housing, Communities and Local Government

Angela Rayner, the ministry’s secretary of state and the deputy prime minister, has been tasked with building 1.5m new homes, and will face severe pressure from the housing lobby, who made substantial donations to the Tory party. They will be arguing strongly that they will need as little red tape as possible in order to build the number of new homes including regulations to make new dwellings low-carbon. The future homes standard is still being drawn up, and there are key decisions to be made, such as whether to require all new homes to have battery storage as well as solar panels and high-grade insulation. Doing so would save householders significant sums but would cost more upfront for the developers.

And then there is the problem of retrofitting the UK’s existing housing stock; the £13bn Labour has promised to spend will barely cover the insulation needs of social housing – how to incentivise the rest is the next question.

Verdict: Rayner must take on the property lobby now, or homeowners will end up paying more later.

Department for Energy Security and Net Zero

For DESNZ, decarbonising the power sector by 2030 – one of Labour’s five missions – will be impossible to achieve without sweeping reforms and repairs to the UK electricity grid, which will take years and tens of billions in investment, of which National Grid has so far promised about £30bn.

The department will also be responsible for setting out the UK’s international commitments under the Paris climate agreement. A new nationally determined contribution (NDC) – the UN term for an emissions-cutting plan – is due by next February but could be unveiled as early as November, at the UN Cop29 climate summit. Campaigners would like to see a target cut of more than 80%, compared with 1990 levels, by 2035 – but that may be too ambitious for other departments.

Verdict: It’s got to be all about grid, grid, grid – without this fundamental underpinning, decarbonisation cannot succeed.

Department for Environment, Food and Rural Affairs

Farming produces about 12% of the UK’s emissions, but the government is planning to cut the nature-friendly farming budget after some years of underspend by the Tories. Farmers say this will also reduce their ability to tackle emissions.

Reed is keen to see much less food waste, and to foster a “circular economy” for all forms of waste, so more initiatives are expected on this. Defra also needs to set out proper plans for the UK’s carbon sinks, such as forests, peat and wetlands, which will need to be planted, maintained and restored as appropriate.

Verdict: Good start, but the decisions get harder from here.

Overarching emissions plan

Underpinning all of these policy areas must be a coherent over-arching plan, adds Tony Bosworth, a climate and energy campaigner at Friends of the Earth. He helped to take the last government to the high court over its carbon-reduction plan – the judges ruled that one inadequate and sent it back. Now it falls to Labour to draft a new one that will set out clearly how the UK can meet not just the carbon budgets set by the Climate Change Committee but also its international targets under the Paris agreement.

Verdict: The former lawyer Starmer will have to answer to the judges if Labour falls short on this one.

HM Treasury

And the hardest thing of all – finding the money to make the investments needed.

Reeves began her bid for government vowing to be “the first green chancellor” but since taking up residence in Downing Street, she has become more of a Dr No – cancelling infrastructure projects, warning of a £22bn black hole in public finances, saying no to calls for investment.

Some of the money needed for net zero and the environment will have to come from the private sector – Miliband will rely heavily on energy companies, for instance, and Reed has made it clear that there will be no renationalisation of the water industry – but that can rebound on the consumer, in utility bill rises.

Chris Venables, the director of politics at the Green Alliance thinktank, warns: “The elephant in the room is that without a change of tack by the Treasury, neither the government’s climate ambitions nor those on nature will be delivered. Without public investment we can’t end the sewage crisis and clean up our rivers, without public investment we can’t insulate home and end fuel poverty, likewise we can’t expect the private sector to crowd in without the. Reeves’s overly cautious fiscal approach risks undermining the agenda for environmental and social renewal at the heart of the Starmer project.”

Verdict: Must do better. A mindset that considers net zero purely as a cost and burden, rather than an opportunity for national renewal and an overhaul of infrastructure that will revitalise the economy, will never deliver for Labour – or the planet.