BBC News Climate

After a day of cancellations, Network Rail's chief executive Andrew Haines has warned anyone travelling tomorrow to be mindful of a slow start to the day.

He tells the BBC:

Quote Message: Tomorrow morning is going to be very heavily affected because the first trains in the morning will not be able to start up because people who'd normally be working the night shift won't be signing on for duty.

Tomorrow morning is going to be very heavily affected because the first trains in the morning will not be able to start up because people who'd normally be working the night shift won't be signing on for duty.

It's not all bad, though. Haines says by late morning, "we'll be running a full service" and it's expected that will continue throughout the day.

"So, again, disruption but far less disruption than today," he adds.

It’ll come as no surprise that an increase in cars on the road during the strike period has potentially disastrous consequences for the environment – and us.

Today alone, traffic surged in a number of UK cities, with location technology company TomTom finding congestion levels at 11am were higher than at the same time last week.

The areas included London, which saw an increase of on-road congestion from 38% on 14 June to 51% earlier, Cardiff (from 24% to 29%), Liverpool (from 24% to 30%), Manchester (from 27% to 34%) and Newcastle (from 18% to 20%).

There were also long queues on outer London sections of the M1, M4, A4 and A40. But what does all this actually mean?

“Taking people off trains and putting them on the road is only going to increase congestion and, as a result, air pollution emissions,” Professor Francis Pope, from the University of Birmingham, tells me.

It’s difficult to measure exactly how much the rail strikes will increase air pollution levels in the UK – not only because they’ve just begun but because, as Prof Pope points out, “there’s not yet some magic number [with air pollution] where if you go over it, people know they’re at greater risk”.

“That’s the long term, though. In the short term, for some people you’ll get exacerbations… people with asthma are more likely to get an asthma attack with high levels of air pollution. Certainly that may be a worry," he says.

“Coupled with the high pollen levels at the moment, there are factors here that may impact [people with] respiratory illnesses.”

There’s a wider issue too, according to Lorraine Whitmarsh, professor of environmental psychology at the University of Bath, which is how Britain’s dysfunctional rail network skews attitudes towards climate change.

“This rise in car use will increase air pollution, greenhouse gas emissions and congestion in the short term, but the bigger risk is that these disruptions create longer-term habits – that people start to rely on their cars to travel if they lose confidence in public transport,” she tells the BBC.

“This poses a real threat to both health and the environment.”