On Saturday, I blocked the M4 into Heathrow Airport to protest against the government’s plans to build a third runway. I ran onto the motorway, before being arrested and carried off the road by four police officers. Two other groups locked on to each other with arm tubes, halting traffic into Heathrow at different points in the road, with one group displaying a banner saying ‘Climate Change is a Racist Crisis’. Nearby, despite heavy police presence, 100s, including many locals, took part in a demonstration, chanting 'No ifs, no buts, no third runway' – the promise of the last two prime ministers. In total 15 of us were arrested, in a peaceful act of civil disobedience which was meant to be disruptive.

I did this because I believe climate change is the most urgent crisis facing humanity. This year the summer Arctic sea ice is at its lowest since records began over 125 years ago. If we allow Greenland’s whole ice-cap to melt, sea levels could rise by around six metres, flooding many of the world’s major cities. Extreme weather events – hurricanes, tornadoes, flooding, failed monsoons – are already wreaking havoc around the world. Sea level rises and degradation of agricultural land in the global south will deprive millions of their right to economic development, abandoning them to hunger and malnutrition. By 2050, it is estimated that hundreds of millions of people could be forced to flee their homes.

As the mother of a young child, I cannot stand by and watch while future generations' chance of life on a habitable planet is taken from them by short-term thinking. For years I have gone on marches, signed petitions and written to MPs. I even stood for election as councillor after joining a political party two years ago. But when the government makes decisions that are contrary to the wishes of local people and councils (see Heathrow's third runway and fracking in Lancashire and Yorkshire) then we have been badly let down by democracy. Our climate is already changing and it isn't going to wait for the next political cycle. If the government won't act in our collective best interests and for the good of all humanity and the natural world, then it is up to you and I.

Some will think our action is pointless and unfair – stopping hardworking families from going on holiday. But this representation is not accurate. Only 15% are responsible for 70% of UK’s international flights – so airport expansion doesn’t really benefit the average person who goes on holiday only once or twice a year. And a large proportion of Heathrow flights are short haul. These routes could be better serviced by improved rail infrastructure. We had prime ministers elected on no-ifs-no-buts promises, yet, last month, Theresa May approved a third new runway. Thousands will see their lifelong homes destroyed and it is estimated that around 150,000 people would find themselves under a flight path for the first time, with a plane overhead every 90 seconds. Climate change is a local crisis; it is a crisis of democracy.

Climate change is also a racist crisis and a colonial crisis. The UK has historically emitted more per person than any other country in the world and yet is one of the least vulnerable to climate change. It is black communities, particularly in the global south, that will suffer most of all. 7 of the top 10 countries affected by the climate crisis are in Sub Saharan Africa.

It is estimated that about 15 million people in Bangladesh alone, a country with extreme vulnerability to rising sea levels and a long legacy of colonial exploitation, could be on the move because of climate change, causing the largest migration in human history. We have a collective responsibility to sort out this mess.

Flying is the most emissions-intensive form of transport and the fastest growing cause of climate change. Even without a new runway, aviation will use up 1/2 of the UK’s climate budget by 2050. If Heathrow expands, it would be responsible for more emissions than any other single site in the UK, including the UK’s largest power station. It is simply not possible for the UK government to expand airports and meet existing commitments on climate action.

Of course, the government knows this, which is why their response has been to simply ignore the issue. When they initially announced the decision to build a new runway, they failed to even mention climate change. All criticisms have been deferred to the findings of the Airport Commission, whose half-baked analysis argues that climate change can be avoided by simply hiking the price of plane tickets in the future. In other words – build more runways but fly less planes by out-pricing most normal people.

Increasing aviation capacity at this stage is like driving a car towards a cliff edge and slamming the acceleration instead of the break. Theresa May’s decision makes no sense for the local community, who are opposed to the expansion, or for the vast majority of the world’s population, for whom climate change is truly an existential threat.

When the government fails in its duty of care, we must become the solution we’ve been waiting for. This is why I took action to on Saturday, and why many more will continue to take action to make sure this catastrophic project does not go ahead.

Road block. Image, protesters.