The Ghost of Humanity’s Future: what do the experts say?

In this article, the second of a series of three, GLOBUS Editor-in-Chief Todd Olive will seek to describe the current state of global climate affairs, detailing predictions by the Intergovernmental Panel on Climate Change and the World Bank regarding the very serious danger to human and natural systems of leaving our climate emergency unchecked.
People in this country have had enough of experts.
At least, they had as of June 3rd 2016, according to British politician Michael Gove (Mance, 2016). In a distinct stroke of luck for this correspondent, however, the Intergovernmental Panel on Climate Change, a global group of experts in the various scientific disciplines that make up the field, remains very much alive and kicking: their 2018 Special Report on 1.5 Degrees forms the basis for this correspondent’s whistle-stop tour of why global warming actually matters.
The Paris Climate Agreement committed the international community to “[endeavouring] to limit” global mean temperature increases to 1.5 degrees above pre-industrial levels by the year 2100 (BBC, 2017): a target that, according to independent analysis group Climate Action Tracker (2018), we are on course to soar past, with a 66% or greater chance that we will only limit warming to below 3.2 degrees. Without significant further action, therefore, the current state of affairs is far beyond bleak: the outlook that this correspondent will present assumes that warming is restricted to 2 degrees.
The key risk in this difference is in the idea of ‘tipping points’. Much like a boulder being pushed over a hill, tipping points are largely unknown points in global atmospheric and environmental systems beyond which the damage caused by climate change would ‘run away with itself’ – with little or no hope of climate systems returning to their current state in the shortened lifetime of human existence anticipated in such a scenario. The analysis below, therefore, should be viewed with some trepidation – for it only embodies a small part of the truth about where humanity is currently headed.
Key Impacts on Human & Natural Systems
The key impacts of climate change are broadly split by the literature into two categories: human, and natural. The sceptical among us would point out, however, that humanity cannot truly be separated from its natural surroundings: impacts on natural systems, such as fishery stocks or land biome distributions (for example, desertification), will invariably have knock-on impacts on the human populations that are reliant on them.
As the range of impacts is so large, this correspondent feels that it would be impractical to produce a fully written summary of the impacts – indeed, the IPCC’s 2018 report has a 138-page chapter dedicated to the potential impacts at 1.5 and 2 degrees. As such, we offer an itemised overview list of the critical impacts at 2 degrees of warming:
- Freshwater
- Additional 8% of the world’s population in 2000 exposed to new or aggravated water scarcity
- This discounts the impacts of population growth of approximately 1.5 billion people since 2000 – and the potential for significant future population growth, particularly in developing countries
- Global population exposed to risk of river flooding nearly triples
- Nearly half a billion people are exposed to severe drought
- Additional 8% of the world’s population in 2000 exposed to new or aggravated water scarcity
- Terrestrial ecosystems
- Approximately 20% of insects and 10% of vertebrates will lose more than half of their global habitable area
- Up to 20% of major ecosystem types will be fundamentally altered by climatic changes
- All regions of the world, particularly North America and the Caribbean, will be at significantly increased risk of wildfires
- Ocean systems
- 99% of coral reefs will be irrevocably destroyed
- Marine foodwebs will be significantly disrupted, severely curtailing the ability of marine species to migrate and reproduce
- Coastal protection and fisheries will be severely diminished by ocean acidification and elevated sea temperatures
- Sea level rise coupled with greater magnitude and intensity of storms and precipitation will lead to widespread loss of coastal ecosystems, with human infrastructure and livelihoods destroyed on a huge scale as a consequence, particularly in low-lying areas
- Extreme loss of sea ice habitats is anticipated
- Coastal systems
- 613th km2 of land will be exposed to total flooding by sea level rise
- 151 million people will be directly impacted by the loss of land to sea level rise, without considering the knock-on impacts on human systems of consequent refugee trails
- Health & food systems
- Significant changes in the productive capacity of ecosystems are anticipated, threatening food security
- Significant changes in the viable locations for food production are anticipated, moving away from lower latitudes towards more northerly and southerly locations
- Risks of illness due to heat-related conditions including occupational heat stress, lack of access to sufficient water, or undernutrition, are significantly increased
- Threat from ozone-related mortality and poor air quality are significantly increased as capacity to cope is eroded
These impacts are, typically of the IPCC, measured and restrained by the need for concrete scientific process to reinforce conclusions: indeed, many of the impacts in the IPCC’s own summary table (Table 3.5, Chapter 3) are quantified only in categories of low, medium, high, or very high, assessed from the literature “by expert judgement” where needed (IPCC, 2018: 247). The World Bank, in its overview of current literature, last updated October 2018, offers some more stark assessments:
Without mitigating measures being taken urgently, climate change could squash an additional 100 million people into poverty by 2030 – let alone 2100.
By 2050, impacts described by the IPCC and beyond could mean that nearly 150 million people in three major developing regions will become refugees of our climate emergency, forced to flee from vulnerable and exposed homes.
Direct costs to health could reach $4bn per annum by 2030, while reduced crop yields and more intense extreme weather events will exacerbate difficulties faced by global agricultural systems in feeding a projected 10 billion people by 2050.
The impact of natural disasters will be exacerbated to cost $520bn each year, equivalent to 20% of the UK’s gross domestic product (World Bank, n.d.), forcing a further 26 million people – nearly half the UK’s population – into poverty every year. More than a decade ago, Professor Lord Nicholas Stern’s review of climate economics, known as the Stern Review, predicted that global income could be irrevocably hobbled, with 20% of global GDP being lost each and every year as a consequence of climate change (Stern, 2007) – without the benefit of 12 years of subsequent scientific advancement in understanding the true potential impacts of unchecked greenhouse gas emissions.
The Consequences: Knowns, Known Unknowns, and Unknown Unknowns
With climate change, as in any modern research discipline, there are three kinds of knowledge – first alluded to in a now-widely known response to a question regarding terrorism and weapons of mass destruction given by then-US Secretary of Defence, Donaldn Rumsfeld, at NATO HQ on 6th June 2002.
The first of these are “knowns”. These are issues that we have identified as threats, theorised about, researched, and made a concerted effort to predict and quantify: sea level rise or global mean temperature increases, for example. While there may be uncertainty involved in these calculations, we at least have some idea of the magnitude of change that we are likely to be looking at.
Next, there are known unknowns. Most obvious of these are in complex issues associated with global biodiversity and ecosystem services: due to the vast amount of data involved that would need to be gathered, verified, analysed, and interpreted, there is no one global assessment of the likely true impact on species extinction caused by climate change of different severities.
Finally, and perhaps most ominously, there are the unknown unknowns – the threats lurking in the darkness that we have yet to even materially anticipate, let alone quantify or attempt to protect ourselves against. It is in the face of these unknown unknowns that we should perhaps be most motivated to take unprecedented action to end the climate emergency.
Why?
Take the issue of previously-mentioned tipping points: by many measures, these are known unknowns. While we acknowledge that they exist and, to some extent, will seek to take action to avoid cresting their hill, we cannot accurately predict at what point individual atmospheric or environmental systems will reach them: at what point will the vast quantities of methane frozen in Siberian permafrost be released by sudden thawing? How much ocean warming might it take for Antarctic glaciers to collapse, such as the 113,000 square-mile Thwaites Glacier, which scientists predict could cause sea levels to rise by over one metre? (Bodkin, 2018)
Beyond these known unknowns, however, lie what could only be described as nightmares: could the melting of Siberian permafrost release new diseases against which we have no immunity? Could changing equatorial cloud patterns lead to the total elimination of rainfall across the African Sahell?
To some extent, these questions are dramatised for effect; with the unprecedented pace of changes that we are imposing on our planetary systems (University of Bristol via Physics.org, 2016), however, we must consider the very real possibility that new threats, possibly of civilisation-ending magnitude, will arise, above and beyond the very real, potentially civilisation-ending threats already posed by climate change (Butler, 2016; Carrington, 2018; Frank et al, 2018).
So what’s the lesson here?
Climate ‘realists’ are wrong. (Olive, 2018a; Olive, 2018b; Olive, 2019) Governments are taking insufficient action to address an existential threat to our home. (Climate Action Tracker, 2018) Our world, our home, our way of life, are all under threat – because we aren’t taking the action that we could to protect them all.
So, the time has come. Our climate emergency is here, now: so let’s make some fire.
Join GLOBUS Editor-in-Chief Todd Olive on Saturday 12th January for the third part of this series on our climate emergency.
Header Image: Photo by Lubo Minar on Unsplash
References
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