A few weeks back, the government presented its ​“vision and strategic framework for achieving net zero aviation by 2050”. The Department for Transport claims to be able to deliver this while simultaneously increasing the UK’s air capacity by 70%, or 200 million passengers above 2018 levels, by 2050. This would require expanding most of the UK’s major airports.

The strategy is irresponsible and dangerous. It represents the epitome of the ​‘burn now and cross our fingers something will save us later’ philosophy which has led our climate to the brink. In its document, the government presents four future scenarios for aviation. Despite their claims, none of these scenarios present a ​‘net-zero aviation sector’. To believe this, you need to perform mental gymnastics which are impressive by even this government’s standards.

Here are the main events in the government’s Olympic pentathlon of nonsense:

1. Pretend non-CO2 emissions from aviation don’t exist, or don’t contribute to global heating

Aeroplanes don’t just emit carbon dioxide — they also pump out water vapour, aerosols and nitrogen oxides at high altitude. Yet for more than a decade, the government and the aviation industry have hidden behind the complexities in the science of these impacts. In this latest strategy, the government has once again put their fingers in their ears and not taken account of non-CO2 impacts.

An array of recent studies suggest combined aviation emissions heat up our planet three times more than CO2 alone. The government presents no plan to tackle this impact, so the unrestricted aviation growth they propose would likely increase it significantly. As aviation’s non-CO2 emissions are unregulated, this alone means the government’s claim to ​“deliver net zero aviation by 2050” is simply untrue.

2. Ignore the lifecycle emissions of so-called ​‘sustainable aviation fuels’

Right now, planes are powered mainly by kerosene fuel. But the government’s scenarios suggest that ​‘sustainable aviation fuels’ (SAFs), which are biofuels usually made from plant material and sometimes waste, will replace a significant proportion of kerosene and therefore reduce emissions by 100%, net. This is because, while they are growing, the plants which are burned as biofuel extract CO2 from the atmosphere.

But in reality it’s not that simple, and astonishingly, in its own appendix, the government debunks its own claim, stating ​“we expect SAF use to deliver over 70% emission savings relative to the use of kerosene”. The basis for assuming a 100% emissions saving is that this is in line with ​“formal [emissions] accounting rules”. But greenhouse gas emissions will cause more flooding, storms and heatwaves regardless of the convenient accounting rules the government uses. Over the past two decades, this same dystopian logic and the adoption of biofuels as an easy alternative to oil and gas has led to the destruction of vast swathes of the world’s most valuable ecosystems.

3. Start praying for a tech miracle

Two out of government’s four scenarios describe a breakthrough in technology, such as hydrogen power, electric flight or sustainable fuels, which would mean flying no longer creates greenhouse gas emissions. Improvement in these areas is already assumed in the other scenarios, but in these two, things are going to go really really well. There could be a ​‘breakthrough’ which, for example, sees the uptake of supposedly ​‘sustainable’ aviation fuels surge eight times higher. No evidence is provided to suggest this breakthrough will take place, it’s merely wishful thinking.

4. Gamble on offsets

Despite the Olympic assumptions in the government’s four scenarios, in three of them the aviation industry is still producing very significant emissions in 2050: between 9 and 36m tonnes of CO2 a year. This could be nearer 100m tonnes of CO2 equivalent emissions if the government weren’t ignoring non-CO2 gases – that’s almost three times the present-day emissions of Wales.

To deal with these ​‘residual’ emissions and fudge its claims, the government proposes using ​‘direct air carbon capture’ (DACCS), a technology which will suck dangerous carbon dioxide out of the air. Putting aside that no solution is proposed for non-carbon emissions, DACCS, the government claims, will be a ​“relatively cheap and cost-effective removal measure” by 2050. These technologies do not, however, currently exist in any scalable form. DACCS might arrive on the scene in the next 28 years, but it won’t be soon and we can’t be sure. And if it does emerge, there is likely to be a lot of competition between sectors and nations for the available DACCS capacity – we cannot guarantee that aviation can rely on this new tech.

5. Ignore what happens between now and 2050

In the most believable of the government’s four outlandish scenarios, the aviation sector’s emissions are only cut by 13% between 2018 and 2035. Over the same period, the UK economy needs to cut its overall emissions by 65%. There is little-to-no scope for other sectors to pick up the aviation sector shortfall as many are themselves significantly underperforming. Preventing climate breakdown is not just about hitting net zero in 2050 - what happens on the way there is perhaps even more important.

An ideology (or perhaps just incompetence) underpins the scenarios set out in the plans, and after two years of mismanagement of the Covid-19 pandemic, it’s all sounding a bit familiar. Throughout the pandemic the UK government repeatedly delayed action to tackle the spread of coronavirus citing uncertainty in the science, scepticism about what the public were willing to accept, and the economic costs of action. Time and again the results were the same: the UK ended up with the worst of both worlds — mass death and higher economic damage.

When it comes to pandemics, acting earlier and harder delivers both the best health and economic outcomes. This lesson must be translated into climate action. The government’s desire to enable short-term greed and delay puts us all at risk.