Aiming for zero emissions is not enough to reduce global warming. MRA Consulting Group’s Mike Ritchie explains the mechanics of climate change and why we should be incentivising negative emissions.
There is a lot of misunderstanding about how far we need to go to lower emissions and reduce global warming.
Let’s use Australia as an example. Australia emits more than 500 million tonnes of carbon dioxide equivalent (CO2-e) each year.
Think of the atmosphere like a reservoir or a bath tub. New emissions are like the tap filling the tub.
Our household/transport/agriculture/industry/waste emissions “tap” is pouring 500 million tonnes per year into the tub. The tap has been turning up each year pretty much since European settlement.
We turned the tap down a bit during the emissions trading scheme then turned it up again once the price signal was removed. On a positive note, it has started to trend down again in the past few years with the rapid acceleration of renewables and their increasing replacement of coal (Figure 1).
Note I have left out land-use and tree clearing (LULUCF), as savings there distort the overall trend of emissions from the economy. The fact that we have slowed widespread tree clearing in Queensland is a good thing, but it should not mask what is happening in the broader economy.
In short, the Australian tap is pouring at about 500mt CO2-e per year – and we are just one tap pouring into a global bathtub.
We need to reduce our emissions to zero. For every year we allow the tap to pour, global warming rates will rise. When we get it to zero emissions globally, climate change will stabilise at that higher temperature. We are at 0.8°C above pre-industrial levels now.
Every year we continue to pour emissions in, temperature will continue to rise.
The temperature only falls, if and when, we get to Negative Emissions. That is, the tap is turned completely off, and we are draining carbon dioxide out of the bathtub. (That is negative emissions).
But unlike our bathtub analogy there is no plug at the bottom of the bath we can conveniently pull out to get it draining quickly. With greenhouse gases in the atmospheric bathtub, apart from growing plants, there are no known or available “technology plugs” we can pull to make a material difference.
That is why everyone is looking at tree planting, natural revegetation, algae etc. We know photosynthesis by plants sucks carbon dioxide out of the atmosphere. We can also sequester the plant material in biochar and compost etc to drive negative emissions.
“What about clean coal?”, I hear someone ask. Even assuming it becomes financially feasible, and that is a big if, it does nothing to reduce the level of the bathtub. It just makes the coal burning contribution to the tap flow equal to zero. It doesn’t reduce the volume in the tub. So, it would be neutral. A good thing but still an emerging technology at best.
We need to go further. We need to incentivise negative emissions. Not just to get our emissions to zero, quickly, but to get to negative emissions. That means billions of dollars into research, supercharging photosynthesis systems and inventing negative emissions technology.
The recent IPCC report states we are not doing enough. We know what to do but we need to fund it, price it, and drive it.
And I have not talked about reinforcing feedback loops. The warmer it gets, the faster that warming might become. Many scientists fear irreversible tipping points. There are plenty we know of. We have to get temperature down fast, so we don’t tip over these thresholds.
We have already had too many people suffer from floods and fires and we have only just started the climate change journey. I am sorry to say it is going to get a lot worse before it gets better.
My view is government needs to lead. Fast.
For more information, contact info@mraconsulting.com.au
Mike Ritchie is Managing Director of MRA Consulting Group. He was National Vice President and NSW President of the Waste Management Association of Australia, chair of the National Carbon Committee, Advanced Waste Treatment Committee and a member of the Resource and Energy Recovery Committee. He has been a senior manager of Local Government, Visy, Waste Services NSW and SUEZ. and is currently a member of ACOR, WCRA, ASBG and the Institute of Company Directors.