Saturday, 19 September 2020

The Cambridge Climate Change Charter: why the urgency?

Earlier this month Cambridge launched its Cambridge Climate Change Charter, to encourage residents and businesses in the city to reduce greenhouse gas emissions. Alongside this there is a carbon footprint calculator, and a broad menu of suggestions actions you can take with advice and guidance, provided by Cambridge Carbon Footprint. Please do sign the charter and make pledges. This is a follow up to the council declaring a climate emergency last year. It seems this is a good time to remind ourselves of why this is an emergency and how long have we got.

I'd like to show you a graph. This is from the carbon budget report for Cambridge from the Tyndall Centre for Climate Change Research. They have determined science based budgets for cities around the UK based on the commitments made in the UN Paris Agreement. There is a short video about the project here. The graph shows historical emissions up to 2019 and the decreasing budget to 2070.

Carbon budget for Cambridge from the Tyndall Carbon Budget report. In the report the image is interactive so do follow the link. Historic emissions from 2015-2019 dropped around 4% per year, mainly due to cleaner electricity at national level. The budget requires reductions of 12% per year to 2050. That is about an 80% drop by 2030

Emissions reductions up to now are mainly due to the increasing share of low carbon electricity 
Over the last few years the drop in emissions was about 4% per year. To achieve the target for 2050 we need to reduce emissions three times as fast, adding up to a drop of three quarters between 2019 and 2030. The 4%/year up to now has been mainly due to more renewable electricity supplied by the National Grid. We have not had to change anything to do this, it all happened on our behalf. However, electricity only gets us so far - we need to change the way we heat our homes and how we travel as well, and businesses need to do their bit too. 

A large part of remaining emissions are from transport and gas heating - that means us.
Here is another chart from the Cambridge Climate Change Strategy Progress Report. It shows the sources of carbon emissions from energy use in Cambridge 2017. 

Chart from Cambridge Climate Change Strategy Progress Report 2018-2019

This shows just over half the emissions are from transport and domestic energy use. Of the domestic energy use about two thirds is due to gas heating. That means us! Personally, we have halved our gas use in our victorian detached house, mainly by installing insulation. For those who like the numbers, our gas use including hot water in winter comes to about 23 kWh/m2/year. That is good but not brilliant  and we are looking for the best way to convert to electric or hybrid heating. (If you are too, come to 'A heat pump for your home' on 12th October.)

Emissions from food and other goods are outside the city boundary but still important.
The Tyndall budgets cover only home energy and transport because those emissions come within the city boundaries. Emissions from food and other goods and services is mostly from outside but they are at least as significant and reducing them is similarly urgent. CCF''s footprint calculator and the charter cover the whole lot.

The council is responsible for 1%. It has an action plan and has made a start. Have you?
Business has a massive role to play too, and the council plans to do what it can. Its share is small - only 1% - but every bit matters. Currently half its emissions come from leisure centres such as swimming pools and its vehicle fleet. Its actions so far include installing solar PV panels at several leisure centre sites and energy efficient flood lighting for sports centres. It is gradually replacing its vehicles with electric powered versions. It now has a pool of electric bikes for staff to borrow and they can also use ultra-low emission and hybrid vehicles from the local car club (read their report for details).

Showing leadership and willingness to adapt generates confidence for investors
Reducing emissions is important but we need to show leadership too - this goes for both individuals and businesses. This can mean:
  • Taking the time to learning about climate change and actions we can take
  • Talking to friends and family about what you have done or would like to do - sharing your stories and challenges
  • Making your pledges public
  • Sponsoring or otherwise getting involved in environmental group
As we demonstrate our willingness to adapt our own lives, it tells our government - at both local and national level - that we do care and we really do want them to spend our money on our future wellbeing. This applies to other investors too. To accommodate more electric cars we need to install more charging points but there is no certainty that there will be customers for them. Would you invest in them now? (See Electric Blue - a new kind of sustainable investment.) Another example - given that we have to move away from gas, it was encouraging that the Climate Assembly endorsed banning new gas boilers from 2030-2035 (see my last post) - but is that soon enough, given that we ought to reduce emissions by three quarters in 10 years? Maybe that target is too hard, what do you think would be sensible? Even a straight line path to net zero in 2050 would mean a reduction of a third in 10 years.

Which brings me to the most difficult issue -why is this so urgent? There are a number of reasons for this.

At the global and local level, we are already seeing climate change effects. 
Recent forest fires in Australia and in the USA are attributed to climate change. Heatwaves in the UK (remember the record 38.7C in the Cambridge Botanic Garden July 2019?) are much more frequent due to climate change. Flooding too: peak river flows are increasing, and flooding is more frequent (see this explainer from Carbon Brief). Intense wet weather early this year and then a long dry spring have had serious impacts on our agriculture - in particular a record low wheat harvest (though I gather it was good for apple orchards). Intense weather is one of the most reliable symptoms of climate change.

Change is happening faster than expected - our models are not keeping up.
Our climate models are good but not perfect. A number of the changes we see are happening faster than we expected. For example scientists are concerned about the rate of polar ice melting - The melting is overtaking the climate models we use to guide us, and we are in danger of being unprepared for the risks posed by sea level rise. [Dr Tom Slater, from the Centre for Polar Observation and Modelling at the University of Leeds, reported in Science Daily] This year we have also seen unprecedented fires in melting peat bogs in Siberia. Both of these processes are implicated in feedback loops that speed up the process of climate change. Although they happen a long way away they have impact on global weather patterns. For more on tipping points, see this Carbon Brief explainer: Nine tipping points that could be triggered by climate change.

An extra 0.5°C of heating makes a big difference to impacts.
The UN Paris Agreement was made nearly 5 years ago and at that time it was agreed that limiting global heating to 2°C was not really enough - we should push for 1.5°C to make this safer. The easier target would mean reducing emissions by 80% by 2050, the 1.5°C target requires net zero. Research since then has shown how important this is. The IPCC brought out a report in 2018 listing some differences between 1.5°C and 2.0°C: doubling the number of people subjected to frequent heatwaves, doubling reductions in crop yields, doubling species extinctions... The WRI has a nice summary here.

In summary
  • Many effects of global heating are very damaging. So far we have tended to underestimate the speed at which they will happen.
  • The sooner we act to reduce the impacts the less draconian we will have to be.
  • A science based carbon budget for Cambridge means reducing our emissions by about three quarters in just 10 years. 
  • Change will not happen by itself - it means action by all of us, individuals, business and government.
  • To stimulate investment in low carbon technology such as electric heating and EV charging points - we need to give investors (of all kinds) confidence that there will be customers.
  • We can provide this by demonstrating willingness to adapt, and talking about it.
Please look at the Cambridge Climate Change Charter and if you are a resident please sign it make some pledges. 

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