Net Zero by 2050
Happy Monday (or Sunday, depending on where you are in the world) and thanks for sticking around to read Carbon Dispatch #2!
The inaugural Dispatch unpacked the various sources of global greenhouse gas emissions (if you missed it, you can find it here).
This week, we’re tackling a related topic: Net Zero by 2050.
It sounds … important. It was all the rage in 2021. But now it feels too late to ask: what exactly is it?
Net Zero by 2050 🧐
‘Net zero’ refers to net zero emissions. We talk about ‘net’ rather than ‘absolute’ zero to acknowledge we may still need to emit small amounts of CO2 in the long term — but if we do, we have to cancel out those emissions through activities that capture carbon before it enters the atmosphere, or remove carbon from the atmosphere, thus keeping our ‘net’ emissions at zero.
The idea of net zero isn’t that controversial any more (at least, in most quarters). As of December 2021, 76 countries have formally submitted their net zero targets to the UN, and another 60 or so have proposed or are discussing a net zero target. Most, but by no means all, are planning to reach net zero by 2050.
Why 2050?
Under the Paris Agreement — the global deal struck between 196 countries in 2015 — we are, as an international community, aiming to limit global warming to well below two (and preferably 1.5) degrees Celsius, compared to pre-industrial levels.
To give ourselves a decent chance of limiting global warming to 1.5 degrees, scientists predict we need to ‘peak’ our CO2 emissions as soon as possible, and reduce them to net zero by midcentury. Alongside this reduction in CO2 emissions, we must achieve deep cuts in other greenhouse gases, like methane.
Why do we need to limit warming to 1.5 degrees Celsius?🥁
As last week’s dispatch highlighted, human activity is causing global warming — we’re already experiencing average global temperatures about 1.1 degrees above pre-industrial levels. To prevent the worst impacts of climate change, we need to grind that warming to a halt before average global temperatures exceed 1.5 degrees above pre-industrial levels.
It’s not all rosy at 1.5 degrees (i.e. 70-90% of coral reefs are still predicted to die☠️) but the impact of global warming escalates with every extra fraction of a degree. For example, at two degrees of warming, almost no coral reef would survive … and two to three times as many species would be lost as at 1.5 degrees 🦤.
Sounds terrible, right? So why aren’t we aiming for no increase in global temperatures, or at least less than 1.5 degrees? In short — scientists think even 1.5 is pretty ambitious, given the current state of play. There’s still *technically* a pathway, but it’s slipping away quickly — we will likely hit 1.5 degrees of warming by the early 2030s without dramatic change 🥵.
This chart from Nature gives you a sense of how global emissions have risen over the last 60 years — and just how significant a turnaround to net zero would be.
So what does 1.5 degrees have to do with net zero by 2050?
The extent of global warming (i.e. temperature increase) is related to the total amount of greenhouse gas in the atmosphere, not our emissions at any given point in time. Think of it like a bathtub, where the running tap represents our emissions, and the water in the bath represents greenhouse gases in the atmosphere. It’s the bath’s water level that determines the world’s temperature, not the tap — although the two are obviously related 🛁.
This means we can’t just stop emitting at some point in the future and expect everything to go ‘back to normal’ 😬. While CO2 and other warming gases don’t stay in the atmosphere forever, they hang around for a quite a while (anywhere from decades to thousands of years).
If we want to limit the extent of global warming to below 1.5 degrees, we have what scientists call a ‘carbon budget’ (to mix metaphors: a limit to how much water we can put in the bath). At some point our budget will run out — we want to make sure we have an emissions-free economy by this point, or sooner.
For a decent chance at limiting average global temperature increase to 1.5 degrees, scientists think we have about 500 gigatonnes of emissions left in the bank (that was from the beginning of 2020, so we’ve already used some of it). Globally, we’ve emitted well over 30 gigatonnes of CO2 per year for the last decade, and that number is creeping up every year (minor blip for Covid in 2020 notwithstanding).
It’s important to note that the carbon budget idea is central to the net zero by 2050 target. We could keep emitting at current rates, before slashing our emissions to zero between 2045 and 2050 — but we’d way overshoot our carbon budget and our 1.5 degree temperature goal 🏦🧨. So ‘net zero by 2050’ isn’t that useful unless we think about our pathway to net zero. As I mentioned above, scientists think the best pathway to achieving a 1.5 degree limit requires peaking our emissions as soon as possible, before bringing them down to (net) zero by 2050.
This graphic from James Ha at the Grattan Institute helpfully illustrates this point:
The bad news🙅
As a globe, we’re not on track to meet net zero by 2050. Even if all countries meet their current pledges and targets — already a pretty tall order — we’re still tracking to around 2.1 degrees of warming.
The good news🥳
We’ve made real progress in the last few decades as clean energy costs have plummeted, and there’s an unprecedented amount of money and attention flowing towards this issue. It’s going to take concerted effort, serious international coordination, and bold government action to get us there.
Topical island 🏝
The “Sharma” Case (Minister for the Environment v Sharma)👩⚖️
On 15 March, the Federal Court of Australia overturned a historic climate-related ruling by deciding the Australian Environment Minister does not owe Australian children a duty of care to protect them from the impacts of climate change when deciding whether to approve projects such as coal mines under the country’s environmental protection regime. (Last year, in an unprecedented move, Justice Mordecai Bromberg sided with eight children in their class action lawsuit against the Environment Minister, in which they argued that she does owe them a duty of care when making such decisions; that ruling has now been overturned).
The Court’s most recent decision is a blow for climate activists, who are, worldwide, turning to the judicial system for support in the fight against climate change as governments twiddle their thumbs. But many judges and lawyers, even those sympathetic to the cause, see climate policy as a matter to be resolved through democratic process (e.g. the Parliament) rather than the legal system.
Dutch courts have produced some landmark climate decisions, requiring very specific government and corporate action on climate change. For example, a Dutch court ruled in 2015 that the Netherlands had to reduce emissions by 25% before 2020 compared to 1990 levels, and decided last year that Shell must reduce its global emissions by 45% by 2030, compared to 2019 levels.
However, European legal systems often contain human rights provisions that make a ‘duty of care’ argument easier to win than in Australian law.
This won’t be the last time Australian courts are forced to consider climate issues. Globally, the total number of climate-related court cases has doubled since 2015, and according to the London School of Economics’ Grantham Institute, is dramatically on the rise. Australia has the highest per capita count of climate cases in the world.
Great Barrier Reef experiences another bleaching event 🐠🪢
The Chief Reef Scientist confirmed last Friday that the Great Barrier Reef has suffered its fourth bleaching event in seven years, and its first in a La Niña year.
While the Government is pouring billions into reef clean-up and protection, scientists say the only way to stop the reef from dying is to stop global warming.
Increasing water temperatures are the main cause of coral bleaching. Reefs can survive bleaching, but it puts them under severe stress, increasing their risk of disease, starvation, and death.
A Paris Hilton-backed woolly mammoth revival to combat climate change? 🦣
A group of bioscientists in the US have raised USD$75 million in their quest to resurrect mammoths, who would supposedly help in the fight against climate change by stomping down snow and insulating melting permafrost (frozen arctic ground that’s melting and releasing greenhouse gases).
Paris Hilton is an investor.
What in the world … 🙊
Feel like you’ve witnessed a lifetime’s worth of world events in the last two years? For Greenland sharks, which are thought to live between 250 and 500 years, 2020-2022 has been a blip. It’s possible this guy’s been cruising the Arctic since Henry VIII was King of England.
And a shoutout to Will Moisis for correctly guessing last week’s ‘Where in the world’: it was Tirich Mir, a mountain in Pakistan — the highest in the world outside the Himalayas.
Tips? Questions ? Feedback?👩💻 —> isabella.borshoff@gmail.com
(I’d love to hear what topics you think would be useful in a future newsletter.)