Why we’re looking for chemicals in the seabed to help predict climate change

File 20190128 108370 ansjbe.jpg?ixlib=rb 1.1
Alex Fox, Author provided

Hidden in even the clearest waters of the ocean are clues to what’s happening to the seas and the climate on a global scale. Trace amounts of various chemical elements are found throughout the seas and can reveal what’s going on with the biological reactions and physical processes that take place in them.

Researchers have been working for years to understand exactly what these trace elements can tell us about the ocean. This includes how microscopic algae capture carbon from the atmosphere via photosynthesis in a way that produces food for much marine life, and how this carbon sequestration and biological production are changing in response to climate change.

But now scientists have proposed that they may also be able to learn how these systems were affected by climate change long ago by digging deep into the seabed to find the sedimentary record of past trace elements. And understanding the past could be key to working out what will happen in the future.

Trace elements can teach us an amazing amount about the oceans. For example, ocean zinc concentrations strikingly resemble the physical properties of deep waters that move huge quantities of heat and nutrients around the planet via the “ocean conveyor belt”. This remarkable link between zinc and ocean circulation is only just beginning to be understood through high-resolution observations and modelling studies.

Dissolved zinc concentrations in the oceans.
Reiner Schlitzer, data from eGEOTRACES., Author provided

Some trace elements, such as iron, are essential to life, and others, such as barium and neodymium, reveal important information about the biological productivity of algae. Different isotopes of these elements (variants with different atomic masses) can shed light on the types and rates of chemical and biological reactions going on.

Many of these elements are only found in vanishingly small amounts. But over the last few years, an ambitious international project called GEOTRACES has been using cutting-edge technological and analytical methods to sample and analyse trace elements and understand the chemistry of the modern ocean in unprecedented detail. This is providing us with the most complete picture to date of how nutrients and carbon move around the oceans and how they impact biological production.

Carbon factories

Biological production is a tangled web of different processes and cycles. Primary production is the amount of carbon converted into organic matter by algae. Net export production refers to the small fraction of this carbon bound up in organic matter that doesn’t end up being used by the microbes as food and sinks into the deep. An even smaller portion of this carbon will eventually be stored in sediment on the ocean floor.

As well as carbon, these algae capture and store a variety of trace elements in their organic matter. So by using all the chemical information available to us, we can get a complete view of how the algae grow, sink and become buried within the oceans. And by looking at how different metals and isotopes are integrated into ancient layers of sedimentary rock, we can reconstruct these changes through time.

Sampling the seabed.
Micha Rijkenberg, Author provided

This means we can use these sedimentary archives as proxy records of nutrient use and net primary production, or export production, or sinking rates. This should enable us to start answering some of the mysteries of how oceans are affected by climate change, not only in relatively recent Earth history but also in deep time.

For example, as well as enlightening us on active processes within the modern ocean, scientists have analysed what zinc isotopes are in seabed fossils from tens of thousands of years ago, and even in ancient rocks from over half a billion years ago. The hope is that they can use this information to reconstruct a picture of how marine nutrients have changes throughout geological history.

But this work comes with a note of caution. We need to bring our knowledge about modern biogeochemistry together with our understanding of how rocks form and geochemical signals are preserved. This will enable us to be sure that we can make robust interpretations of the proxy records of the prehistoric seabeds.

Collecting the samples.
Micha Rijkenberg, Author provided

How do we go about doing this? In December 2018, scientists from GEOTRACES met with members of another research project, PAGES, who are experts in reconstructing how the Earth has responded to past climate change. One approach we developed is to essentially work backwards.

First we need to ask: what archives (shells, sediment grains, organic matter) are preserved in marine sediments? Then, which of the useful metal and isotope signatures from seawater get locked up in these archives? Can we check – using material from the surface of deep-sea sediments – whether these archives do provide useful and accurate information about oceanic conditions?

The question can also be turned around, allowing us to ask whether there new isotope systems that have yet to be investigated. We want to know if GEOTRACES uncovered interesting patterns in ocean chemistry that could be the start of new proxies. If so, we might be able to use these ocean archives to shed light on
how the uptake of carbon in marine organic matter responds to, and acts as a feedback on, climate in the future.

For example, will a warmer world with more carbon dioxide enhance the growth of algae, which could then absorb more of this excess CO₂ and help to act as a break on man-made carbon emissions? Or will algae productivity decline, trapping less organic matter and spurring on further atmospheric warming into the future? The secrets could all be in the seabed.

This blog is written by Cabot Institute member Katharine Hendry, Reader in Geochemistry, University of Bristol and Allyson Tessin, Visiting research fellows, University of Leeds.  This article is republished from The Conversation under a Creative Commons license. Read the original article.

What global threats should we be most worried about in 2019?

The Cambridge Global Risk Index for 2019 was presented on 4 December 2018 in the imposing building of Willis Towers Watson in London. The launch event aimed to provide an overview of new and rising risk challenges to allow governments and companies to understand the economic implications of various risks. My interest, as a Knowledge Exchange Fellow working with the (re)insurance sector to better capture the uncertainties embedded in its models, was to find out how the index could help insurance companies to better quantify risks.

The presentation started with the Cambridge Centre for Risk Studies giving an introduction on which major world threats are included in the index, followed by a panel discussion on corporate innovation and ideation.

The Cambridge Global Risk Index quantifies the impact future catastrophic events (be they natural or man-made) would have on the world’s economy, by looking at the GDP at risk in the most prominent cities in the world (GDP@Risk). The Index includes 22 threats in five categories: natural disasters and climate; financial, economics and trade; geopolitics and security; human pandemic and plant epidemic; and technology and space.

Global Risk Index 2019 Threat Rankings (Cambridge Global Risk Index 2019 Executive Summary)

The GDP@Risk for 2019 for the 279 cities studied, which represents 41% of the global GDP, has been estimated to be $577bn or 1.57% of the GDP of 2019. The GDP@Risk has increased since last year by more than 5%, which was caused by both an increase in GDP globally and a rise in the chances of losses from a cyber attack and other threats to richer economies. Risk is becoming ever more interconnected due to cascading threats, such as natural hazards and climate events triggering power outages, geopolitical tensions triggering cyber attacks sponsored by states, conflicts worsening human epidemics, and trade wars triggering sovereign crises, which in turn caused social unrest.

Nonetheless, the GDP@Risk can be reduced  by making cities more resilient, that is improving the ability of a city to be prepared for a shock and to recover from it.  For example, if the worst off 100 cities in the world would be as prepared as the top cities, they could reduce their exposure to risk by around 30%, which shows the importance of investing in resilience and recoverability. This is a measure of what the insurance industry calls the “protection gap”, how much could be earned from investments to improve the preparedness and resilience of a city to shocks. How fast a city recovers depends on the ability to access capital, to reconstruct and repair factories, houses and infrastructure, to restore consumers’ confidence and to reduce the length of business interruption.

Global Risk Index 2019 Growth by Sub-Category ($, bn) (Cambridge Global Risk Index 2019 Executive Summary)

Natural catastrophe and climate

After a 2017 with the second highest losses due to natural disasters, 2018 saw several record-breaking natural catastrophes as well. This year we have experienced events from magnitude 7.5 earthquakes and tsunami in Indonesia, which caused more then 3000 deaths, to the second highest number of tropical cyclones active in a month, from Typhoon Mangkhut in the Philippines, to Japan’s strongest storm in the last two decades. Hurricanes have beaten records too, with hurricane Florence in North Carolina becoming the 2nd wettest hurricane on record, which caused $10 bn losses, and hurricane Michael in Florida reaching the greatest wind speeds ever recorded, which caused $15 bn losses.

Floods in 2018 caused heavy death tolls in Japan and south India, with 225 and 500 fatalities respectively, the former showing the weakness of an ageing city infrastructure, while the latter raising criticism on poor forecasting and management of water resources. Droughts raged in South Africa, Australia, Argentina, Uruguay and Italy reducing harvests, while wildfires in California were the largest on record, which caused $20 bn losses. Extreme events have made it to weather events too, with extreme heatwaves, as the hottest summer in the UK, comparable to the one of 1976, and the heatwave in Japan which hospitalised 35,000 people, as well as with extreme freeze, as the “Beast from the East” in the UK which caused losses estimated at $1 billion per day.

Extreme events are becoming ever more frequent due to climate change, with the next few years expected to be anomalously warm, even on top of the regular climate change. This hints that the rising trend in losses due to natural catastrophe and climate is not due to stop.

Devastation from the cyclone in Tonga, 2018.

Finance, economics and trade

Market crash is the number one threat for 2019, which could cause more than $100 billion in losses. Nonetheless global financial stability is improving due to increased regulation, but risk appetite has increased as well due to positive growth prospects and low interest rates, which increases financial vulnerabilities. Trade disputes between the US and China and the US and Europe are disrupting the global supply chains. The proportion of GDP@Risk has increased in Italy due to policy uncertainty and increased sovereign risks, while in countries such as Greece, Cyprus and Portugal sovereign debt risks have decreased following restructuring of their debt and country level credit rating upgrades.

Geopolitics and security

The risk from geopolitics and security worldwide has remained relatively similar compared to last year, with roughly the same countries being in conflict as in 2017. Iran’s proxy presence remains in conflicts in Yemen, Iraq, Israel, Syria and Lebanon, while social unrest has increased risk in Yemen, Nicaragua, Venezuela, Argentina, Iraq and South Africa. The conflict in Yemen has caused the world’s worst humanitarian crises in 2018, with more than 2 million displaced, with food shortages and malnutrition causing cholera outbreak. The total expected loss from this category is similar to the one from financial, economic and trade risk.

Technology and space

Technology and space is the category with the lowest expected GDP at risk. Nevertheless, the risk has increased over recent years, with cyber attacks becoming ever more frequent due to the internationalisation of cyber threat, the increasing size and cost of data breaches, the continued disruption from DDoS attacks, the threat to critical infrastructure, and its continuous evolution and sophistication. Cyber attacks have climbed one level in the ranking this year, assuring the 6th overall position. In 2017 the WannaCry ransomware attacks affected 300,000 computers across 150 countries disrupting critical city infrastructure, such as healthcare, railways, banks, telecoms and energy companies, while NotPetya produced quarterly losses of $300 million for various companies. The standstill faced by the city of Atlanta when all its computers were locked due to a ransomware attack in March caused £2.6 million to be spent, and another $9.5 million are expected. This attack highlighted the breath of potential disruption, with energy, nuclear, water, aviation and manufacturing infrastructure at risk. Moreover 66% of companies are estimated to have experienced a supply chain attack, costing on average $1.1 million per attack. In response to these threats, countries are increasing their spending on cyber offensive capability, with the UK spending hundreds of millions of pounds. Power outage, nuclear accident and solar storm are not at the top of the threats ranking globally, but solar storms could cause over $4bn of GDP@Risk in North American cities, due to their position in northern latitudes, leaving 20-40 million people without power.


Health and humanity

The greatest threat to humanity according to the UN is anti-microbial resistance, with areas in the world already developing strains of malaria and tuberculosis resistant to all available medicines. It is expected that over the next 35 years 300 million people will die prematurely due to drug resistance, decreasing the world’s GDP between 2 and 3.5% in 2050. Major epidemics have remained largely constrained in the same areas as last year, and are fuelled by climate and geopolitical crises which aggravates hygiene and public health, such as the Yemen and Somalia cholera outbreaks. Plant epidemics have not increased, with the ongoing problems of Panama disease in bananas, coffee and wheat rust, and the xylella fastidiosa still affecting olive plants in southern Europe.

Corporate innovation and ideation discussion

The panel discussed the importance of the Cambridge Global Risk Index to prepare companies for future threats. For example, for insurance companies including the index in their management of risk would allow them to be better prepared and more profitable. I found the words of Francine Stevens, director of Innovation at Hiscox, particularly inspiring. She talked about how the sheer volume of research produced is often too large to be digested by practitioners, and how workshops might help to bring people with similar interests together to pull out what are the most exciting topics and challenges to work on. As a Knowledge Exchange Fellow myself, this strikes a familiar chord, as it is my job to transfer research to the insurance sector and I have first-hand experience on the importance of adopting a common language and identifying how industry uptakes new research and methods.

Francine has also talked about the importance of collaboration between companies, a particularly sensitive topic in the highly competitive insurance sector. This topic emerged also at the insurance conference held by the Oasis Loss Modelling Framework in September, where the discussion touched on how non-competitive collaborations could bring the sector forward by avoiding duplication. Francine’s final drop of wisdom was about the importance of diversity to drive innovation, and how having a group of smart people with diverse backgrounds often delivers better results than a group of high-achievers with the same background. And this again sounded very familiar!

This blog is written by Cabot Institute member Dr Valentina Noacco, a NERC Knowledge Exchange Fellow and a Senior Research Associate at the University of Bristol Department of Civil Engineering. Her research looks at improving the understanding and consideration of uncertainty in the (re)insurance industry. This blog reports material with the consent of the Cambridge Centre for Risk Studies and is available online at https://www.jbs.cam.ac.uk/faculty-research/centres/risk/news-events/events/2018/cambridge-global-risk-index-2019-launch-event/.

Dr Valentina Noacco