The Ministry of Defence (MoD)  Global Strategic Trends programme has issued an  updated report on the threats and opportunities for world peace and security out to 2045.

Climate change is one of several megatrends considered by the report. And it’s a big one – it will affect  every region of the world through impacts like rising sea levels, drought and food shortages, the report finds.

But what are the most significant climate impacts expected by the MoD?

All-encompassing

First of all it’s worth noting that climate change features heavily in the MoD’s analysis. Almost every section of its report, from transport to energy to health, makes reference to climate change impacts.

People often talk about ‘ mainstreaming‘ climate change into all aspects of policy-making or decision-taking. It looks like the MoD has taken this to heart.

Perhaps because its impacts are so all-encompassing, climate change is mentioned more frequently, with 151 references, than growth (98), water (141), health (85), energy (147) or migration (34). We’ve made a Wordle of 25 of the most frequently used words in the report, excluding common ones such as “likely”.

This prominence reflects growing military concern over climate change as a ‘threat multiplier’ that can exacerbate existing problems as well as creating new ones.

Climate inertia

The MoD gives a brief run-down of what is expected to happen as our climate changes over the next 30 years.

The much-discussed global warming “pause” is nothing special, It says. Periods of slow-down and speed-up in surface temperature increases have happened before and are likely to happen again, as excess heat energy is absorbed or pumped out by the ocean.

Some climate impacts are inevitable even if emissions stopped tomorrow, the MoD notes, because of inertia in the climate system. That means temperatures in 2045 are likely to have increased by 1.4 degrees above late 20th century averages, for instance. And sea levels are likely to rise by between 32 and 38 centimetres by 2050.

Despite climate inertia the MoD thinks cutting emissions is likely to be the most important way to manage climate change in future. It warns against relying on geoengineering techniques such as pumping sulphates into the stratosphere to engineer a cooler climate.

The report says:

“Over-reliance on particular geoengineering technology to mitigate the effects of climate change could also render users vulnerable to catastrophic effects if equipment failed or was sabotaged. It is not clear therefore what, if any, role geoengineering will play by 2045 in countering the effects of climate change, and the extent to which it could heighten international tensions.”

Flooding, food prices and migration

The MoD thinks coastal flooding, climate-driven migration and rising food prices due to drought and water stress will be some of the most significant impacts of climate change over the next 30 years.

There are already between 270 and 310 million people at risk of coastal flooding. Without adaptation to climate-driven sea level rise this could increase by more than a third, the MoD says. The risks are being amplified by rapid urbanisation and the location of many Asian mega-cities in coastal areas.

The most dramatic impacts of sea level rise will be felt in small island states. This week the Pacific islanders of Kiribati bought land in Fiji to insure themselves against rising sea levels. The MoD says:

“By 2045, a growing number of low-lying islands could be at risk of near total submersion – displacing entire communities.”

Climate change is one of the factors that will drive an estimated 96 million people to migrate between 2010 and 2050, and the UK will be one of their main destinations, according to the report.

“Migration is likely to increase, with people moving within, and outside, their country of origin to seek work or to escape the effects of climate change. Climate change is likely to drive some people from areas that are particularly badly affected, although not everyone who wishes to leave is likely to be able to do soâ?¦ The main estimated net receivers of migrants are likely to be the US, Canada, UK and Australia, while the main estimated senders are Bangladesh, China, India and Mexico.”

We’ve taken a detailed look at climate change and migration on  several  occasions . It is far too simplistic to raise the spectre of millions of climate migrants arriving in the UK en masse. But climate change is likely to add to forces already at work as people move from rural areas to cities and from cities to the developed world.

The MoD points out that developing countries will probably feel the effects of climate change most acutely and will be least able to spend money adapting to its consequences. The money needed for humanitarian aid is expected to soar by 1,600 per cent over the next 20 years, “in large part due to the effects of climate change”, the MoD says.

Another factor driving migrations will be drought, heat stress, desertification and the consequent impact on food production. Droughts and heatwaves are likely to increase in frequency and duration, the MoD says. The impacts of climate change on crop yields are complicated but will be negative on average across the world.

It says:

“When the effects of climate change are taken into account, the [food] price increase above present levels could be as much as 100 per cent.”

Catastrophic climate change

One particularly stark scenario considered by the MoD would see worse-than-expected “catastrophic climate change” after only limited action to reduce emissions. This isn’t a prediction – it’s a low probability outcome that the MoD thinks needs consideration because of the potentially high impacts.

This scenario would see temperature rises leading to long heat waves in temperate zones like Europe, sustained droughts contributing to repeated harvest failures and severe food shortages. This could lead to “sudden mass migration” across national borders and “widespread social unrest”.

It’s interesting that the MoD considers this a credible, if unlikely, scenario. There has been a lot of debate over the extent to which it’s possible to draw links between climate and conflict.

What might be notable is that the MoD is the only part of government doing this sort of long-range analysis, according to futurologist Ian Shields who was involved in earlier versions of the global strategic trends report.

Some people say this long view should influence wider government decisions. But since when did politicians look beyond the next election?