💭 Our changing climate and the road ahead

Notes from a members briefing with Dr Emily Shuckhurgh
💭 Our changing climate and the road ahead


Following a recent members-only briefing with inventor Bill Gross on how our sustainable future will be powered by renewable energy and innovations in energy storage, I was curious to delve deeper into the root causes and solutions to the grand challenge of climate change. That’s why I invited climate scientist and mathematician Dr Emily Shuckburgh to be my guest in the State of the Exponential briefing series.

I first met Emily in the 1990s. She now co-leads the Polar Oceans division at the British Antarctic Survey, which is focused on understanding the role of the polar oceans in the global climate system. Emily is a fellow of Darwin College, a member of the Faculty of Mathematics, an associate of the Cambridge Centre for Climate Change Mitigation Research, an associate fellow of the Centre for Science and Policy, a member of the Cambridge Forum for Sustainability and the Environment.

A new initiative led by Emily will be launched later this year at the University of Cambridge, aiming to bring together the full breadth of interdisciplinary research, education and innovation across the university to help inform and deliver a resilient, sustainable carbon neutral world.

Emily is also working on taking the findings of climate research to a broader audience. She published Climate Change in collaboration with HRH The Prince of Wales and environmentalist Tony Juniper to bring the issue closer to all citizens.

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6 things you should know about climate change, risks and opportunities

  1. Emily started her talk with a powerful unequivocal message: climate change is human-made and is the result of our collective actions.

If we look at how the world has been changing over the past 150 years, we notice a dramatic increase in global GDP—a transformation due to industrialisation. The engine powering industrialisation itself is energy-use which, in turn, is powered by fossil fuels which produce carbon dioxide when burned—the famous ‘greenhouse gases’. As the amount of carbon dioxide in the atmosphere increases, the temperature of the surface of the Earth also increases. Moreover, sea levels have also steadily increased more than 25cm due to two causes:

  • First, as Earth’s temperature increases so does the ocean temperature causing water to expand in volume which then results in higher sea levels.
  • Second, high temperatures cause ice in polar regions and glaciers to melt and this water finds its way into the oceans. While both causes contribute to the rising sea levels, polar ice melting is increasing and will become a primary cause for the rest of this century.
  1. Today’s atmosphere is unprecedented in human history, prehistory and beyond. Emily explained how the ice cores which scientists drill from the Antarctic ice sheet provide clear evidence as to how the climate has changed in the past.
What you see in the photograph, there is a slice through one of those ice cores. And you'll notice that there's lots of tiny little bubbles in that ice. What happens is that as the snow falls in Antarctica, it traps tiny bubbles of air with it. As snow piles up layer upon layer upon layer, it means that when we drill down through the ice - we can drill down more than three kilometers deep - we are able to recover the actual air that was in the atmosphere hundreds of thousands of years ago and determine what both the atmosphere and the climate were like in the distant past.

Emily explained that the natural cycle of climatic change involves carbon dioxide levels going up and down over an extended period of the Earth's history. Those changes are driven by very, very slow variations in the orbit of the Earth about the Sun that occur over long time periods. When we are a bit closer to the Sun in terms of the Earth's orbit, the carbon temperatures are higher and the carbon dioxide levels are higher—the reverse scenario is also true. The natural cycle involves 180 and 280 parts per million carbon dioxide. Compare that with today’s staggering figure of more than 415 ppm. This proves that today’s climate change is not part of the natural climatic changes.

  1. Greenhouse gas emissions continue to increase… year on year despite global agreements made in Paris in 2015.

While emissions from India and China seem to be on the increase, there is a slight decrease in emissions in the US and Europe. Interestingly, international transport is increasing Y-o-Y and it is a significant contributor to emissions, but is not being captured in the country inventories.

  1. We are already experiencing increased risk of extreme weather due to climate change.

A meta-analysis of 200 studies by CarbonBrief assessed how climate change affects extreme weather around the world. The scientific conclusion is that extreme events have increased or substantially increased due to climate change.

Emily shared some examples:

  • In the UK we saw extreme flooding events in recent years. As the world warms up, so does the atmosphere. The problem is that a warmer atmosphere is able to hold more water vapor in it. More water in the atmosphere means it is more likely to rain down and heavy rainfall events, increasing the risk of flooding.
  • Moreover, the severe flooding events associated with the hurricanes that hit the United States and Caribbean were amplified by a warmer atmosphere holding water vapor to rain down and causing heavy rainfall events. Storm surges are able to reach much further inland causing much greater flooding as a consequence of the rising sea levels.
  • Last but not least, climate change interacts with natural events such as El Niño, making those events much more severe. El Niño occurs when sea temperatures in the tropical eastern Pacific rise 0.5 °C above the long-term average.

The warming also increases risks of a catastrophic shock. The ice cores in Greenland shown in the graph above tell us that in the past there have been dramatic and rapid changes in temperature fluctuations. However, increased temperatures may end up in dramatic changes. ‘One of the great concerns is changes to the ice sheets in the polar regions, both in Greenland and in West Antarctica.’ The collapse of these ice sheets would be indeed catastrophic resulting in devastating infrastructure damage and large-scale displacement of populations. For example, the Thwaites Glacier is contributing 5% of the sea level rise and there are signs that it may be irreversible damaged.

  1. Time is running out to keep below 1.5°C; currently on-track for 3°C by end of century.

The challenge is that even the most ambitious pledges of the Paris Agreement are not enough to prevent temperatures from exceeding 1.5°C. The scientific consensus is that there is a certain amount of carbon dioxide we can put into the atmosphere before we exceed a certain temperature threshold, ‘the carbon budget’.

As Emily put it:

If we look at the carbon budget for keeping temperatures below 1.5°C, then we find that we have about 2600 or so billion tons of carbon dioxide in that budget. But we've already spent the vast majority of that: we've already put some 2200 billion tons of carbon dioxide into the atmosphere. And that means we've only got another 400 billion tons of that budget left to spend. But we're currently emitting carbon dioxide at about 40 billion tons per year. So you can do the simple arithmetic, that means we've got about a decade or so left, burning fossil fuels, deforestation and other sources of carbon dioxide emissions before we exceed the budget for 1.5. And that is where the number that you sometimes hear quoted recently of those 12 years left to solve the climate problem comes from.

We need to reach net-zero globally by 2050 for 1.5°C. The scale of the challenge is monumental: it requires reversing the increase in emissions which we have seen in the past four decades, in a single decade by 2030 by half and reaching net zero by 2050. But more than that, we need to actively take carbon dioxide out of the atmosphere until the end of the century in order to reach net negative emissions.

  1. Risks and opportunities for businesses and investors.

Emily is of the opinion that we need to take a balanced view of both risk and opportunities of climate change. The key risks include physical risks to assets, transition risk through competition and liability risk from litigation actions. However, there are significant opportunities for building climate resilience and hence protecting assets and supply chains, clean growth through smart investment strategies and reputational in terms of brand awareness and loyalty in an environmentally-aware consumer society. Given that the world's 250 largest emitting publicly traded companies account for around 30% of greenhouse gas emissions, businesses need to do more to reduce their emissions.

An interesting point we’re getting to with technological development is that something like artificial intelligence could help with identification of these risks. Emily is working at the University of Cambridge on developing AI-based tools to provide climate risk assessments to inform risk to business operations, human well-being and nature.

What to take away

The facts and evidence we have make it impossible to deny that not only is climate change real but that it is happening at an unprecedented pace. Reversing the existing damage and preventing future perils requires transformational change and drastic action. NOW.

We will need to approach this issue holistically as a global grand challenge and this means adopting a systems-thinking approach that will involve thinking about trade offs and engaging multiple stakeholders.

Please share your thoughts below!


P.S. Thanks to Diana Foltean for research and editorial assistance.

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