Dr Torill Bigg, Chief Carbon Reduction Engineer at Tunley Engineering discusses how the UK is halfway to net zero carbon emissions.

There has been a lot of discussion recently on the exciting news that the UK is halfway to net zero carbon emissions. We are also halfway through the timeline from the baseline set at 1990 levels to the net zero goal set at 2050 – 30 years have passed and there are 30 years to go. So, the news that UK emissions have halved at the halfway point would seem reason for optimism. It would suggest we are on track. And things can only get better as individuals become ever more aware and ever more environmentally conscious.

Increasing numbers of businesses are measuring, reporting, and reducing their carbon footprints. Households and businesses are replacing cars fuelled by dinosaurs with cars fuelled by electricity. And the UK government seem confident, announcing the latest carbon reduction target of 78% by 2035 – exactly where we would be if today, we are halfway there. But is it all as it seems?

In 1990’s the UKs GHG (Greenhouse Gas) emissions stood at 794 million tonnes of carbon dioxide equivalent. That is the baseline for the UK’s climate goals, including the net zero target under its legally binding Climate Change Act and its international pledge to the Paris Agreement. That is to say that net zero was formulated in law as cutting greenhouse gas emissions to at least 100% below 1990 levels by 2050.

It has taken 30 years – and a pandemic – for UK emissions to fall 51%. 2020 alone saw a drop in carbon emissions estimated at between nine and 17%. However, there will be an end to the pandemic, or at least an end to its economic impact. This will inevitably slow our progress to net zero. Indeed, many are predicting an energy use boom. And further deceleration may be caused by the inclusion of international aviation that is currently excluded. Or by inclusion of emissions associated with UK consumption of goods and services imported from abroad. The shipping industry itself has now called for a new global carbon tax.

There are further factors that have brought us to our 51% reduction. These have genuinely reduced carbon emissions. For a start there has been an irreversible move away from coal. In 1990 coal made up two thirds of electricity generation; the power sector was the largest contributor to the nations emissions. Oil power made up 10% of generation, two percent came from renewables.

Then there are CFCs; 1990 is the year that the Montreal Protocol was strengthened to ban CFCs in industrial countries – and by 2010 in developing countries, the economies of many of which have since thrived and indeed become more industrialised.

CFCs (Chlorofluorocarbons) are greenhouse gases much more potent than CO2 itself, and so their removal contributes a much larger proportion from the CO2 equivalent measure.  Methane is also a greenhouse gas that is much more potent than carbon dioxide itself. 1990’s landfills lacked the emissions controls of today, so much more methane leaked from landfill, gas fields and the UK coal mines which are now lost.

Notwithstanding the as yet unknown balance of that most potent of greenhouse gases, sulphur hexafluoride (SF6). SF6 is necessary in electricity distribution, such as will be needed for the increasing move over to electricity. SF6 has 22,800 CO2e per kg, primarily because it remains in the atmosphere for 3,200 years; the very quality of stability that makes it so useful as a gas insulator in our electricity substations.

If we are to continue to build on our success with carbon emission reductions to date, perhaps we should not rush to popular solutions. Instead let us step back and make valid and considered choices that will genuinely reduce our carbon footprint as individuals – and so each of us make our contribution to cutting carbon emissions worldwide.

Dr Torill Bigg:

Torill has written a number of articles looking at carbon reduction (examples attached) and she would be more than happy to put something relevant together for you. Her work here at Tunley Engineering over the last 10 months has helped cut carbon emissions by 4,000,000kg of CO2e; she works with companies to assess their Carbon Footprint and develop roadmaps to net zero.