Dr. Emily Shuckburgh is a climate scientist at the British Antarctic Survey. Therefore, she is at the forefront of observing the dramatic and shocking changes in our ice sheets and greenhouse gas levels. Read on for part one of Emily’s powerful article, in which she highlights the high environmental and economic risks of continually elevating CO2 levels.
Preventing damaging climate change impacts requires dramatic and rapid emissions reductions.
By Dr Emily Shuckburgh
Central bankers worry about financial stability. By contrast, polar scientists such as me fret about ice sheet stability. Yet it is increasingly clear that the latter is at risk from climate change and could threaten the former.
Today’s atmosphere is unprecedented throughout human history, prehistory and beyond. To find equivalent levels of CO2 you have to travel back in time more than three million years. Ancient air bubbles recovered from the Antarctic ice sheet tell us how CO2 levels have varied naturally in the past, demonstrating that the dramatic increase since the industrial revolution lies far outside the natural cycle.
The physics of the “greenhouse effect,” which explains how more CO2 in the atmosphere leads to warming, has been known since the mid-nineteenth century. Consistent with this understanding, the temperature, averaged over the surface of the land and oceans, has increased by about 1°C over the past 150 years. The past three years rank as the warmest on record, with the decade being on-course to be the forth in a row of record-breaking warmth.
The impacts of climate change are already being felt here and now. Around the world, meteorological records are being broken again and again, as what were once extreme conditions are starting to become normal. Evaluation of recent extreme weather events has revealed numerous cases where the risk of occurrence has increased as a consequence of the climate change we have already seen.
For instance, analysis indicates that the kind of heavy downpours responsible for some of the terrible flooding of recent years in the UK have become more likely because of climate change. The result has been billions of pounds worth of damage.
Nations agreed in Paris in 2015 to keep temperatures well below a 2°C increase versus pre-industrial times – if possible limiting the rise to 1.5°C. Nevertheless, we are currently on a pathway to reach 3°C by the end of the century.
The greater the warming, the greater the risks to all sectors of society and to the natural world. The IPCC’s recent report methodically articulates how the risks of extreme weather and sea level rise, of species loss and extinction, and of a deterioration in many dimensions of human wellbeing increase substantially from 1.5 to 2°C of warming.
Recent millennia have been characterised by unusual stability, but we know that dramatic and rapid regional change in temperature can occur: there are numerous recorded examples of such “black swan” events in the last 100,000 years. This is a fundamental non-linear characteristic of the earth’s system: it has happened in the past; it could happen in the future. There is evidence, for instance, that catastrophic loss of ice sheets in Greenland and Antarctica, which would eventually result in many metres of sea level rise, could be triggered at around 1.5 to 2°C of warming.
The amount of CO2 that can be released before dangerous levels of warming are reached can be seen as a “carbon budget”. At present rates of fossil fuel use, deforestation and soil damage we are on course to exhaust this budget if we are to have a good chance of staying below 1.5°C within the next 10 to 15 years. Keeping temperatures below 1.5°C requires reducing CO2 emissions dramatically and rapidly to reach “net zero” by about 2050 – and significantly reducing other greenhouse gas emissions at the same time.
Everyone should take careful note. Decisions made across society over the next few years will make a radical difference to our future climate and will determine the fate of future generations.
Climate change is a threat to financial stability
Climate and weather-related events, such as heatwaves, droughts, floods, storms and sea level rise can result in large financial losses through the damage and turmoil they wreak and the knock-on effects. Such events can have a direct financial impact through damage to property and other assets and interuptions to business continuity.
Extreme weather events can also have an indirect financial impact as global supply chains are disrupted or as critical resources become scare or expensive. This can result in widespread impacts on different market participants as these events impair asset values, undermine the ability to repay loans, threaten the creditworthiness of borrowers, result in raised insurance premiums, increase credit exposures, challenge portfolio diversification, and so on. Near-term impacts may also be felt through potential changes in investor sentiment or market expectations around climate risk, or in changes to climate-related regulations.
The increasing frequency of severe weather events could also impact macroeconomic conditions through sustained damage to national infrastructure and weaken fundamental factors such as economic growth, employment, and inflation. This could have implications for the market price of sovereign debt for those countries most susceptible to the physical impacts of climate change.
Many potential systemic risks arising from climate change are only just starting to be identified and the potential for catastrophic shocks to global financial stability triggered as climatic tipping points – such as the collapse of polar ice sheets – are passed is not well understood at present.
An increasing recognition of this complex landscape is leading to questions regarding whether climate-related risks are currently being adequately accounted for.
Look out for part two of this article, coming online in the next few days, which will summarise the current scientific understanding behind the severe risks we are facing as a global community. The third and final blog will soon follow in tow, discussing the challenge of responding to this information so as to limit warming to the less catastrophic 1.5 degrees celsius as recommended in the Paris agreement.