A collaboration by Pete Whelan and Courtney Holder
The Paris Agreement
The Paris Agreement is an international treaty overseen by the United Nations with the stated aim of keeping the rise in mean global temperature to 1.5°C above pre-industrial levels in order to mitigate the effects of climate change. To achieve this goal, emissions need to be cut about 50% by 2030.
This has come to be defined by the term “net zero”, referring to the balance of carbon dioxide emissions and other greenhouse gases with carbon offsetting and the systematic elimination of emissions to create a sustainable carbon footprint.
Under the agreement, each signatory country is accountable for determining, planning and regularly reporting its progress to the United Nations.
Although the Agreement was greeted with enthusiasm worldwide and has been used as a valuable climate litigation tool to force countries corporations to adopt a more climate-friendly approach, individual countries are permitted to withdraw after three years of membership, as US President Donald Trump did in 2020 before his successor Joe Biden rejoined the next year.
Although current pledges are insufficient for reaching the Agreement’s current goals, countries must make successive pledges, each more ambitious than the last.
Studies conducted by Nature found that not a single major industrialised nation had implemented their pledges as of 2017.
Choose Your Own Planet
The IPCC’s Climate Change Reports aren’t exactly page-turners. Much of the scientific jargon contained within the latest report’s 3068 pages, however crucial, is riddled with impenetrable graphs and intimidating acronyms that are quite inaccessible to the layman.
It’s full of astounding research, though, making comprehensive predictions based on the data that analyses trends like the rate of technology development, education, healthcare, population growth and geopolitics, and uses them to predict the future.
Let’s unpack it a little.
At the centre of the report are a concept called SSP’s, or “Shared Socioeconomic Pathways” that are essentially predictions of how the world looks in 2100, depending on the approach the world takes to reducing emissions.
Like a data-crunching choose-your-own-adventure, each SSP tells a different story of human emissions and tells us what happens to the planet along the way.
The number of each SSP is based on the level of ‘radiative forcing’, in watts per square metre by 2100. Radiative forcing is a way of measuring the energy trapped in our atmosphere, which tells us how much temperatures will rise.
Here’s a breakdown of the story a few of the key SSP’s tell:
SSP 1.9 – Everything’s Pretty Much Okay
Remember the Paris Agreement? This is the outcome they’re looking for, and is considered to be quite optimistic. The data tells a story of CO2 emissions hitting net zero by 2050 and our society changing gears from economic expansion to investing in education, health and general well-being. Countries support each other financially to hit their emissions targets.
We see more extreme weather events, and temperatures rise about 1.5°C before dropping to 1.4°C by 2100.
This is the only scenario that meets the goal of the Paris Agreement, though no current pledges support this outcome.
What to expect in 2100:
A small increase in extreme weather events.
Lea levels rise 0.4 metres.
Low adaptation required at a low cost.
An increase in heatwaves and rainfall.
SSP 4.5 – We Keep Doing What We’re Doing
This is the path we’re currently on. Our CO2 levels stay about the same and our society doesn’t change drastically either, although we do make the switch to renewable energy. At about 2050, emissions begin to drop around 2050, but by 2100 we don’t hit net zero and temperatures have risen 2.7°C.
What to expect in 2100:
A moderate increase in extreme weather events.
Sea levels rise about 0.47 metres, causing widespread coastal flooding.
Moderate adaptation required at a moderate cost.
Global food production drops significantly due to extreme heat.
SSP 8.5 – The World Goes to Hell in a Handbasket
This one is pretty bleak. Our economy is booming thanks to our continued investment in fossil fuels and other unsustainable practices, but we’ve already doubled our emissions by 2050. In 2100, global temperatures have risen 4.4°C.
What to expect in 2100:
A huge increase in extreme weather events.
Sea levels rise 0.63 meters, causing extreme coastal flooding.
High level of adaptation required at a high cost.
Parts of the world become uninhabitable in summer due to extreme heat.
So How Are We Doing?
With the release of each Climate Change Report from the United Nations-sanctioned Intergovernmental Panel on Climate Change (IPCC) comes a rash of media headlines decrying a grim future for our planet. “IPCC issues ‘bleakest warning yet’ on impacts of climate breakdown”, writes the Guardian. “’Nobody Is Safe’ Warns Latest IPCC Climate Report’” writes Vice.
The hysteria created by the reports is justified.
The IPCC’s reports project a series of global emissions scenarios, or Representative Concentration Pathways (RCPs), that show us what the planet could like in the year 2100 based on the painstaking analysis of social, political and economic trends.
Dr Josephine Brown is a lecturer In paleoclimate modelling at the University of Melbourne. Her work involves using the same climate models that the IPCC’s uses, and she has recently contributed to an article for Nature Climate Change journal called “Studying climate stabilisation at Paris Agreement Levels”.
We spoke to her to find out more about how these models are put together, and which scenario we’re on track for.
“There’s a really complicated process that goes into putting each scenario together, and lots of different people have to get together and discuss what they think the future could look like. But in the end they try and summarise that into these different scenarios,” Dr Brown said.
Scenarios are the product of the same input data being processed by different predictive models, she explained.
“They’re actually these computer codes that are run by lots of different groups around the world to develop these things over a long time. And they’re similar to weather forecasting models, but they basically calculate the climate.
“Imagine, the model is like the machine and the scenario is like the input that you feed into it.
“So, you feed in a particular input and then the model cranks away and calculates lots and lots of things and spits out some information, which is telling you in 2050 what the climate will be like in 2060 and 2070, 2080, 2090. It’s going to look at lots and lots of different things like rainfall, sea level, temperature, etcetera.”
Based on her work, what scenario does Dr Brown think we’re on track for now?
“So we’re kind of sitting in mid-to-high range at the moment – something like RCP 6 or 4.5. One of the mid-range scenarios. Not on the really bad RCP 8.5.
“But if governments stick to the promises and pledges made in the last few years, it looks like the future could bend down into one of those lower emissions pathways. Some climate scientists are optimistic that we could start to follow a lower pathway in the next decade, if all the governments actually keep their promises.”
The government response to the reports so far has been lacking, Dr Brown said.
“Over the previous decade, there was a lot of really good climate research that was done in Australia and it was pretty much ignored by the Government. People were putting out reports saying ‘this is what we need to do’ and the Government pretty much just put those reports in the filing cabinet and moved on.
“But now I think there’s a bit more of a connection. The new government actually has a department of Climate Change again and they’re a bit more interested in having a science based approach. So that’s definitely a step forward.”
James Ashley, manger of hazard preparedness and response at the Bureau of Meteorology in Western Australia, agrees Australian government has a history of apathy toward climate science.
“My observation would be that in Australia there has been a long term political barrier from vested interests of the fossil fuel sector and so on. I’ve been very close to government and they’ve tended to have an outsized influence over decisions while the renewable sector wasn’t organised enough as a lobby group,” Ashley said.
“I think in the end, change has be led by the government because they’re the ones that tell us what our priorities are as a country and they mostly focus the economy and ignore the climate, so people think, ‘oh, well, climate change must not be that big of a deal.’
“People need to see that something can be done as well, and see the government moving forward otherwise. But it just seems like the same old conversation going around in circles.”
This article was originally published on Shorthand. Click below for original.
