Fiona Harvey is an award-winning environment journalist. She works for the Guardian and previously reported for the Financial Times for more than a decade. She has covered every major environmental issue from as far afield as the Arctic and the Amazon, and her wide range of interviewees include Ban Ki-moon, Tony Blair and Al Gore

Wind, rain and outages: London should be making preparations to deal with more extreme weather.

Transport networks will be the first to go. Many roads, especially near the river, are likely to be closed; lorries may be banned from those that remain open because of high winds. Rail routes into and out of the capital are likely to be heavily affected. Underground and overground services will be shut in many places, if not across the whole network. Sewage pipes will quickly be overwhelmed by the volume of rain, with localised surface water flooding across the capital and the dumping of large volumes of overflow sewage into the Thames. The water delivery networks will struggle, too, with millions potentially left without access to clean water.

This is not some futuristic scenario or a disaster movie. It is the reality of what could happen if a major storm hits London. Given the increasing incidence of extreme weather events recorded by the Met Office and predicted to continue and worsen with climate change, the chances are that something like this will happen sooner rather than later.

If electricity substations become flooded, power cuts are likely. More dangerously, heavy surface water flooding could cause localised ruptures to gas mains, with the poten­tial for leaks. Communications are likely to be more resilient. Many mobile phone masts are located on roofs, meaning that networks should continue to operate, although they may be swamped by traffic as people try to make contact with family and friends. Broadcast media should also be unaffected, enabling television and radio messages from police and government, at least to those whose electricity or mobile phone is still working. But the shops can only continue to supply food for about four to five days and if they were to run out, the breakdown of law and order wouldn’t be far behind.

Climate change is likely to result in a massive increase in floods, droughts, heatwaves and fierce storms. At the climate conference in Paris this December, a key consideration will be how countries and cities can prepare: the United Nations is making it clear that the consequences are not confined to developing countries, although they will be the worst hit because of their lack of infrastructure.

Already, we are experiencing a change in rainfall patterns, with more rain coming in shorter bursts instead of the slow steady saturation we are used to. Britain and London had a scare in 2007, when a storm surge in the North Sea was expected to coincide with high tides, carrying echoes of the disaster of 1953 when hundreds died and water reached record levels in the Thames. This time, the surge did not arrive – in the words of former Department for Environment, Food and Rural Affairs minister Richard Benyon, ‘we dodged a bullet’.

London’s planners are not, of course, ignoring these threats. Scenarios and ‘games’ to test resilience, particularly for the emergency services, are played out regularly. There are big new infrastructure projects designed to protect the capital from the worst effects, including proposals for an updated Thames barrier – the current one, installed as a result of the 1953 disaster, is now raised on a frequent basis, far more often than was envisaged – and for a Thames super sewer that would carry away excess water faster. Both of these will require tens of billions in investment.

Other solutions will require the involvement of citizens: in not concreting over gardens, for example, which raises the risk of surface water flooding. There needs to be increasing preparedness among businesses, for instance through back-up generators and off-site storage of key equipment; more localised electricity generation, through solar panels and small wind turbines; and requirements that infrastructure companies provide details of their plans for a disaster. Engineers have suggested even more drastic measures, such as ‘sacrificial’ streets that would be allowed to flood to save others. (Trying selling that in the London property market.) As we build more much-needed houses in London and its suburbs, we need not only to avoid building them in flood plains (difficult), but also to ensure that their sewage networks are equipped to remove surface water quickly without flooding. That means building to a higher standard.

A key problem with London’s prep­arations is that they go on behind closed doors among government agencies and businesses for fear of frightening people. For true preparedness, the public needs to be involved. We need to be told what measures are being put in place and how they will affect us. Community groups, faith centres, schools and other local organisations should be much more engaged: all will play a key organising role if severe weather strikes and citizens are unable to cope on their own.

Keeping a few bottles of water, tinned goods and candles in the cupboard under the sink should not be the preserve of millennial crazies; it should be standard practice for Londoners.