"After today's G8 summit we agreed to set the aim for a reduction of the entire global emissions of gases to 50 per cent by 2050, as a target to be taken up by the entire world".
This was Japan's Prime Minister Fukuda speaking on behalf of the G8 leaders last Tuesday. What an extraordinary situation: eight people from eight countries setting policy with such huge implications for the whole world. But hey, they said they would halve global emissions – that's got to have been a good thing, right?
First, it's not even a policy. Without stating a base year to make cuts against, it is meaningless. Without setting a mid-term target for 2020, it is un-ambitious. And without a commitment that rich countries will take on the biggest share of cuts, it is unjust. South Africa's environment minister rightly dismissed it as 'an empty slogan without substance'.
The world's climate scientists are clear: we need global greenhouse gas emission cuts of at least 80% against 1990 levels by 2050 in order to stay safely below 2 degrees warming. By "safely" they mean we would still have up to a one-in-three chance of overshooting into dangerous climate change. But this is the safest target anywhere close to being on the table for discussion.
In 1990, global greenhouse gas emmissions were 36 Gigatonnes of CO2e. They're 47 Gt today and rising. By 2050, therefore, they must be just 7 Gt for "safety". Yes, it is hugely ambitious. But the alternative is to choose an irreversible increase in floods, droughts, hurricanes and sea-level rise, which would cause chronic food shortages, water scarcity, homelessness, and health crises for well over one billion of the world's poorest people for generations to come.
So what is the G8 actually proposing?
If they mean that we should halve global emissions by 2050, measured against 1990 levels – the most generous reading we could give to their words – then we would end up with 18 Gt of greenhouse gases in 2050. That's more than double the safe limit.
Or, if what they actually mean – and it's only too possible – is that we halve emissions by 2050, but only starting from now, then that will put us more than three times over the safe limit, at 23 Gt.
This is equivalent to a serious, jailable offence of intentionally drunk driving – and with the rest of the world forced to ride in the back seat. In any other situation, the police would take away their car keys.
Kate Raworth is Oxfam's senior researcher on climate change