Party Manifestos - Climate Comparison

23 June 24

The VoteClimate team has searched the party manifestos to identify any and all policy pledges that would have an impact on the UK's climate emissions. We've done our best to interpret each pledge fairly and to quantify the CO2e reductions/increases that would result.

It may be unsurprising that the Greens come out streets ahead, but there are huge differences between the consequences of the main parties' commitments:

The chart and table below show how many MtCO2e emissions would be avoided if each party's manifesto were implemented as they have promised:

How Do The Main Parties Compare?

Here's a zoomed-in chart to compare the main parties more easily:

Methodology

All the manifestos (except Reform's) are full of warm words about tackling the climate emergency. We have reviewed the policy promises underpinning those ambitions and published a full analysis.

• We took every party at their word - even if their promises looked "ambitious" or were not specifically funded.
• Some pledges are highly ambiguous. In some cases we've had to make an educated guess at what is intended. We tried to interpret them as fairly as possible.
• We have ignored pledges that did not appear to be quantifiable and those where a token action would fulfil the pledge.
• As our baseline we used existing government policies and the pipeline for renewables roll-out.
• We've assumed each policy would continue to 2050, and not be rolled back by a future government.
• We used pre-existing studies to estimate how much CO2e would be mitigated/avoided compared to the baseline for each policy, for each year to 2050.
• For per-person emissions savings, we've scaled Plaid Cymru's figures according to the Welsh population size; for the SNP, we've used the UK population, as their (by far) biggest pledge applies to the UK as a whole.

This analysis has been produced in a hurry and makes large assumptions and approximations. We've tried to capture that with wide (30%) error bars. It's worth noting that where the parties have overlapping policies, eg on EVs and decarbonisation, any errors will be correlated. Eg a 10% error for a particular policy would affect the emissions-reductions totals similarly for each party proposing that policy. This reduces the impact of errors on how the parties rank.

This is still work in progress and inevitably contains some errors. On the other hand, it seems unlikely, given the huge differences between them, that revisions will change where each main party stands in the rankings.

Before telling us we've got it wrong, we would kindly ask that you review our calculation documents (below) for any manifesto commitments we have missed, and let us know if you think we've made any mistakes in our calculations. We are happy to revise if any oversights are identified.

Where a party scores badly in our analysis, that is a reflection of a lack of actual policies on climate in their manifesto.

Constructive comments are welcome. Please send to .

Most Impactful Policies

Here is a sample of the most impactful policies.