Why a Zero Carbon target for 2030?

Since the Paris Climate Change agreement was agreed in 2016 there has been a lot of focus on trying to keep global warming to 1.5C.

We, in the Green Party want to be clear that we fully endorse the world-wide effort to achieve this. And we have looked at the science carefully and we also looked at what a fair share of this effort means for the UK. This fairness is in the Paris Agreement, as well as the temperature target, and is known as equity.

We calculated, using the science and equity, that achieving 1.5C means reducing emissions to zero by 2030 in the UK.

The recent IPCC 1.5C special report, confirms our view.

Take this figure from the special report:

CO2 emission pathways

What this figure shows is that if you want to have a 50% chance of meeting 1.5C then world-wide emissions need to be zero by 2055. But we, in the Green Party, do not want to promote policies which have a 50% chance of failure.

So take a look at the blue line in the figure with zero carbon in 2040. This is what is necessary to have a 66% chance of achieving the 1.5C target. Again not really good enough to have a one third chance of failure. Would you get on a plane with a third chance of crashing? So this is a reason for bringing the zero date earlier for the world.

And that is not all. The figure does not account for equity between countries. If we do adopt the blue line for the UK, we continue to emit more CO2 than the average over that period. This is known as Constant Emissions Ratio. The Green Party does not consider this equitable.

The concept of equity is explained well here and the table is produced here:


Allocation name

Allocation characteristics

Constant emissions ratio

Maintains current emissions ratios, preserves status quo. 
This approach, often referred to as ‘grandfathering’, is generally not considered as an equitable option in climate justice and is not supported as such by any Party.

Greenhouse Development Rights

Countries with high GDP per capita and high historical emissions per capita have low emissions allocation. 
This approach preserves a ‘right to development’ through the allocation of mitigation requirements.


Countries with high GDP per capita have low emissions allocations.

Equal cumulative per capita

Populations with high historical emissions have low emissions allocations. 
This approach allocates to each country total cumulative emissions proportional to its cumulative population over the 1990-2100 period.

Equal per capita

Convergence towards equal annual emissions per person in 2040.


The middle three (boldened) in the table are much more equitable methods of allocating the remaining emissions. And yes, the UK ticks the boxes of having high GDP and high historical emissions. These interpretations of equity have much lower allocations of emissions to the UK and pull the date for zero carbon for the UK far, far earlier than 2040.

In the light of this, we, the Green Party, will continue to argue for Zero Carbon in the UK in 2030.

Do we have all the answers as to how to achieve this? No. But we want to work with anyone who has respect for science, reducing global risk and equity in getting there.

And if anyone tells you zero emissions in 2050 (or even 2040) for the UK is soon enough, ask them what their view on equity is, and what chance of failure are they prepared to risk.


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