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The science on why 2050 is far too late The UN says grave danger lies between 1.5C and 2C. Communicating that in 2 sentences and then linking it to the fact that a 2050 target gives us a 50% chance of overshooting 1.5C, is a quick, simple, incontrovertible justification that uses undisputed science. In a nutshell: - Grave danger lies between 1.5C and 2C - ​cities underwater, crop failure, coral reef collapse, and a risk of setting off irreversible runaway warming - Long-term sea level rise could irreversibly skyrocket between 1.5C and 2C, which could be the difference between large parts of Brighton, New York, Jakarta, Shanghai, and ​countless coastal cities being regularly plunged underwater by storm surges. - We’ll also see a ​sharp rise in dangerously hot days​. Droughts will see millions more around the world​ struggling for fresh water, amid rising crop failure​ and even more deadly heatwaves. For much of India, Bangladesh, and Pakistan, merely stepping outside could be deadly​ by the end of the century. - The impacts on ecosystems, such as coral reefs, will be far more devastating at 2C compared to 1.5C. These impacts will have major knock on effects to agriculture and fish stocks, ​threatening food security​. - Finally, there is a deeply concerning risk of triggering tipping points and feedback loops near 2C of warming, which would ​irreversibly commit​ us to even more warming, sea level rise and ecosystem damage over time. - Global ​2050 target​: - Gives us ​too low odds of limiting heating to 1.5C​ (and so does 2040) - Is based on an outdated budget - ​we have less carbon to play with than we think - In a ​UK context, the 2050 target​: - Ignores responsibility for historic emissions - Ignores the principle of equity - that countries with higher per capita emissions and larger economies should take responsibility to mitigate emissions faster, given greater capability to do so. - Ignores aviation and shipping (until 2033) - huge contributors to global carbon emissions. - Ignores the carbon cost of goods imported from outside of our borders but that are only created because of ​our​ demand for them. - Is ​not even on track to be achieved - ​the UK is on track to meet only 7 out of 24 indicators. - The UK’s carbon budget: - Will be exhausted in 6-8 years, even with dodgy government definitions - Will be exhausted in four years if we include responsibility for historic emissions, and the carbon cost of imports


Net zero by 2050 puts human civilisation at great risk. It gives us just a 50/50 chance of limiting warming to 1.5C, according to the UN. For a two-thirds chance, the UN says we need to hit net zero by 2040. We’ve already passed the date to be sure of keeping temperature rise below 1.5C. And that’s based on a budget for how much more carbon the world can emit that’s​ five years old​. A major UN report (1.5C) last year recommended reducing this latter budget by nearly a quarter, because the current estimate ​does not account​ for the release of methane from the thawing of frozen arctic ground, known as permafrost. This is based on the most probable impact of permafrost thaw. The upper estimate would require us to reduce our budget by more than 80%. And it isn’t the only natural carbon emitter that isn’t modelled by the UN’s estimates, which have been shown to be conservative in the past. So a 2025 target is essential. The reason we don’t want global heating to rise above 1.5C is because dangerous tipping points may lie between 1.5C and 2C – beyond which we could set off processes that irreversibly accelerate heating, flooding, and ecological collapse. - Long-term sea level rise could irreversibly skyrocket between 1.5C and 2C, which could be the difference between large parts of Brighton, New York, Jakarta, Shanghai, and countless coastal cities being regularly plunged underwater by storm surges. - We’ll also see a sharp rise in dangerously hot days. Droughts will see millions more around the world struggling for fresh water, amid rising crop failure and even more deadly heatwaves. - 70,000 people died in the 2003 European heatwave. This year, temperatures topping 50C in India and Pakistan caused almost unfathomable suffering. Expect much worse to come. For much of India, Bangladesh, and Pakistan, merely stepping outside could be deadly by the end of the century. - The impacts on ecosystems, such as coral reefs, will be far more devastating at 2C compared to 1.5C. These impacts will have major knock on effects to agriculture and fish stocks, ​threatening food security​. - Finally, there is a deeply concerning risk of triggering tipping points and feedback loops near 2C of warming, which would ​irreversibly commit​ us to even more warming, sea level rise and ecosystem damage over time.

Less (but still) important Even net zero by 2030 may not give us an acceptable chance of limiting warming to 1.5C - but let's assume that's the best the world can do. The UK makes up 1% of the world’s population, but is responsible for 2-3% of emissions to date. So as it’s been using more than its fair share for years, it should use less for the final few decades. That means net zero by 2025.


It also means including the carbon cost of goods imported from outside of our borders but that are only created because of ​our​ demand for them. The government ignores these emissions, and has no plans to include them. Even based on the government’s own inaccurate definition of its emissions, we will have exhausted our carbon budget in 6 years for a 2-in-3 chance of 1.5C. In 8 years for a half-chance. By government calculations, emissions fell 3% in 2018. And by the admission of its own advisers, it is even failing to meet its own shoddy targets. Why? Because 2050 gives the public the illusion of time, when we have none to waste. Failing to deliver immediate and widespread change is significantly increasing cost and risk down the road, it is a policy of irresponsibility that is certain to fail.

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