Nine people were charged today after a protest by Black Lives Matter UK caused major disruption at London City Airport.

The campaign group is the British offshoot of a movement that began in the US in response to a spate of police shootings of unarmed black people.

Initially, BLMUK concentrated on talking about the deaths of black Britons while in various kinds of state custody. But this week the group turned its attention to climate change with the City Airport demonstration.

Protesters – all white – occupied a runway and waved banners that said: “Climate crisis is a racist crisis.”

A BLMUK member, Alexandra Wanjiku Kelbert, later expanded on the reasoning behind the protest in a comment article in the Guardian, and made two interesting claims:

“Britain is the biggest contributor per capita to global temperature change.”

Our issue here is with the word “is”.

The figures used to justify this statement are not in fact based on what is happening now, but on a long historical view.

The original data is from this paper. The authors took an existing estimate of carbon emissions for the whole of Europe since 1850.

Then they came up with an estimate for Britain alone, based on historical records of changes in vegetation cover. The idea is that the more changes there are to forested areas in a country, the higher the CO2 emissions.

Let’s say that this is a fair assumption, and that this data stretching back to the 19th century is accurate.

The resulting claim is that if you add up all carbon emissions since the industrial revolution, Britain has contributed more to global warming, per head of population, than any other country in the world.

This might tell us something interesting about Victorian Britain, but what is the state of play today?

The European Union has the UK in 42nd place for per capita CO2 emissions in 2013. The US Department of Energy puts us at number 53 in the same year.

“Black British Africans are 28 per cent more likely than their white counterparts to be exposed to air pollution.”

The source is this impact assessment produced by the Department for Environment, Food and Rural Affairs, based on figures that are now 15 years old.

It calculates the average exposure to PM10 air pollution by each ethnic group by working out who lives near busy roads.

It’s right to say that people defined as “black or black-British African” are significantly (we make it 29 per cent) more exposed on average than people labelled “white – British”.

But it’s debatable whether this is evidence of racism being directed specifically against black people.

In most of the UK, the researchers found that most of the difference in exposure to pollution was explained by the fact that “there is a greater tendency for ethnic groups to live in more urban areas, which is where the higher emissions are”.

Urban areas are also where the most economic deprivation is, which raises the question of whether all this is just a complicated way of saying that white British people tend to be better off than ethnic minorities.

The figures suggest that increased risk of pollution affects everyone who is not “white British”, including people of Chinese and Irish ethnicity. Whatever this is, it’s not just a black issue.

The underlying data is from 2001. That means it predates the significant immigration from central and eastern Europe that Britain experienced after the enlargement of the EU in 2004.

Where do recent white eastern European migrants fit into these figures? Are they more or less exposed to pollutants than the black British population? We don’t know.

The bigger picture

The broader point made in the Guardian article is that the outcomes of global warming are not felt equally across the world: Britain is less vulnerable to climate change, compared to countries in sub-Saharan Africa.

This idea that the developing world will bear the brunt of the effects of climate change is well established, having been put forward by the Intergovernmental Panel on Climate Change, the United Nations and many campaign groups and think-tanks.

Obviously the focus is now shifting far beyond the experiences of black people living in Britain now.

Even in the scope of one article, BLMUK make claims about so many issues – migrants in the Mediterranean; prisons; employment; education; income inequality – that it’s impossible to FactCheck everything.

Like the American original, the British offshoot began by concentrating on the deaths of black people at the hands of the police, but the central claims were hard to stand up with statistics too.

In a previous Guardian article, another BLMUK member, Laura Barker, wrote:

“People who are black are more likely to end up dead after encountering British police or being held in custody… the people that end up dead after interactions with police, or immigration officers, or prison officers, are disproportionately black and brown.”

She provided a link to figures published by the charity Inquest, which show 157 deaths of black and minority ethnic people (BAME) in custody and otherwise following contact with the police in England and Wales since 1990.

This is almost exactly 10 per cent of the 1,572 people of all races who died in the same circumstances in that time.

But the latest estimate for the non-white population of England and Wales is about 14 per cent.

So these number don’t appear to suggest that you are disproportionately likely to die in custody of following contact with the police if you are non-white.

There is an obvious contrast to be made with the situation in the United States, even if the figures are not directly comparable.

Of the 157 BAME people who died in Britain since 1990, 11 were shot dead. That works out at about one shooting death every two-and-a-half years.

In America more than 100 black people a year were killed on average by law enforcement personnel between 2003 and 2009.

And in America there is very clear evidence that black people – particularly young black males – are much more likely to die at the hands of the police than people from other races.

The verdict

It’s fair to say at this stage that some of the statistics Black Lives Matter UK have used to make various claims are open to question.

The link between climate change and race in Britain appears to be debatable, on the evidence the group has put forward so far.

And the idea that people from ethnic minorities are more likely to die at the hands of the police in Britain is hard to stand up too.

Obviously, we are only scratching the surface here when it comes to the complex issue of racism in this country, and there may be better statistical evidence of bias against black people elsewhere.

The Ministry of Justice is currently working on a review of the criminal justice system to investigate possible racial bias, after publishing research that shows different sentencing trends for different racial groups.

Data on the various “stop and search” schemes show police are more likely to target black people.