Climate Change

Analysing the threat

Over its long history, the Earth’s climate has changed many times due to a range of factors. Contemporary concern about climate change arises from the observation that human activities are altering the chemical composition of the atmosphere and the inference that this is significantly and dangerously shifting global climatic patterns. Natural changes in the past were slower, smaller or occurred prior to the rise of human civilisation, making our present experience and expectations a novel form of a recurrent phenomenon.

Already we are moving beyond the relatively stable climatic range of the last few thousand years, within which civilisation emerged and developed and upon which much of our present infrastructure and agriculture is dependent. The scope and pace of these changes may well overwhelm the ability of natural and human systems to adapt without major disruptions and discontinuities.

Crucial to the climate system is the role of certain “greenhouse” gases that trap solar energy in the atmosphere, acting like a blanket in reducing heat loss back into space. After water vapour, whose short atmospheric lifespan makes it follow and magnify other changes rather than trigger them, the largest contributor to this effect is carbon dioxide, which is the best known of the greenhouse gases, though methane, nitrous oxide and many other trace gases also play a role. Carbon dioxide has many natural sources and sinks, which are more or less in equilibrium. This means that human emissions, though only a fraction of total emissions, nonetheless have resulted in steadily rising atmospheric concentrations since the industrial revolution. Current levels are around forty percent higher than they were prior to the widespread exploitation of fossil fuels and higher than they have been for at least two million years. Even were human emissions to cease today, carbon dioxide levels and global temperature averages are likely to remain significantly elevated from pre-industrial levels for millennia. Other greenhouse gases are also rising, due chiefly to land use changes associated with the spread of monocultural industrial agriculture.

This enhancement of the greenhouse effect is reinforced by a number of positive feedback cycles that amplify initial changes. For example, increased air temperatures result in higher levels of atmospheric water vapour, a potent greenhouse gas, itself increasing temperatures; similarly, declining Arctic summer sea ice exposes more dark ocean, which absorbs more solar radiation than highly-reflective ice, further increasing the system’s total heat energy. There are also some negative feedbacks that dampen the effects of these changes, but these are outweighed by positive feedbacks in all humanly meaningful timeframes.

The extra energy retained in the system means more than simply global warming of the average atmospheric and oceanic temperatures. The average temperature rise includes a redistribution of temperature patterns, with some areas warming far more than the average, particularly over land in northerly latitudes. Warmer air holds more moisture, increasing the severity of extreme precipitation events. Shifts in ocean and air currents mean altered geographic and annual distribution of precipitation. That is, on average more rain and snow falls, though not necessarily in the same places or at the same times of year as previously. This has serious implications for natural and human agricultural ecosystems. Furthermore, climate change is frequently a multiplier for other ecological problems, lowering the resilience of ecosystems to shocks and pressures such as introduced invasive species, pollution, and overexploitation.

Warmer oceans expand and melt icesheets, both raising sea levels with a wide range of consequences for coastal infrastructure and low-lying islands. Rising carbon dioxide levels pose a further threat to aquatic life through increasing the acidity of the oceans, reducing the ability of many species foundational to the marine food web to access the calcium they require for growth.

Since 1900, average global surface temperatures have risen by about 0.7ºC and most of this has been in the last three decades, with more warming in the lower atmosphere, over land, at high northern latitudes and at night (all features best explained by greenhouse gases being the primary driver of the warming). Already this is associated with a wide variety of effects: melting glaciers, rising sea levels, increasing oceanic surface temperatures and stratification, biodiversity decline and species distributions moving polewards, shifts in the timing of events in the natural world (flowerings, migrations, hibernations and so on), increase in extreme precipitation events and other noted changes in the hydrological cycle and wind patterns, expansion of the tropics, intensification of droughts, altering distribution of infectious diseases vectors, increasing the intensity, scale and frequency of wildfires, increasing frequency and severity of mass coral bleaching events and many more.

Due to a multi-decadal lag between emissions and temperature rise resulting from the slow release of heat from the oceans, the system is committed to at least another 0.7ºC rise from our present levels of greenhouse gases. Depending on future emissions and the precise sensitivity of the climate system as a whole once all the feedbacks are included, temperatures are likely to rise between 2-6ºC by 2100.

The precise extent of the threat is difficult to pinpoint but the mainstream scientific debate ranges between those who fear we may face hundreds of millions of refugees, trillions of dollars in infrastructure costs, thousands of extinctions and widespread loss of habitats, and those who think it could well be significantly worse. If temperatures rise by more than 4ºC, the continuity of industrial civilisation becomes significantly less likely.

Global climate is a highly complex system whose intricacies are still under intense scientific investigation. In particular, the precise role played by cloud and tiny particles called aerosols are yet to be definitively quantified. Therefore, scientific predictions or projections concerning the climatic future retain a measure of uncertainty. It is possible that currently unknown or partially understood negative feedbacks could dampen the predicted rate or extent of change. Yet it is equally likely that currently unknown or partially understood positive feedbacks could exacerbate the situation even further.

However, the primary uncertainty remains the scope and pace of human societal change in response to this rising threat. To what extent will humanity continue to pursue activities that emit climate-destabilising emissions? Of course this question is thorny, given the intimate and variegated ways that the combustion of fossil fuels powers so much of the world’s electricity, heating and transport demands. What mix of mitigation, adaptation and suffering are we collectively willing to bear?

Scriptural and theological reflections

Christian theology has much to contribute to ethical deliberation about climate change. The Christian community that engages in such shared reflections is to be shaped by the gospel of Christ in this as in all things. A theological epistemology informed by an understanding of common grace opens the space for empirical scientific knowledge of the world on which climate concerns are based. A redeemed identity discovered in Christ by grace ensures that believers have no need to seek cultural identity markers in shared patterns of denial, nor to allow fears to lead to repression of threatening beliefs.

A healthy doctrine of creation fosters a profound respect for the integrity of the created order. Humans are not masters over creation and isolated from it but privileged members of the community of creation, belonging with the soil from which we were taken and sharing the breath of life with the community of living beings. God’s blessing upon humanity is shared with the other creatures; the fruitfulness and multiplication of one is not to come at the expense of the other. An awareness of sin and brokenness generates suspicion towards human attempts at dominion that look more like domination than humble attentiveness and mutual blessing. Christian concepts of dominion take their lead from the one who came not to be served but to serve. Faith in Christ summons believers to acknowledge our complicity in the disordering of creation and seek forgiveness and repentance from the ways of life that abuse what we have been given. Receiving creation as God’s good gift needn’t imply there is a given and unchanging ecological or climatic optimum, though will lead to deep concern over the implications for the created order that arise from the pace and scale of change associated with our destabilising of the climate.

Wholehearted love for God expressed in love for neighbour will pay close attention to the particular threats faced by the neighbour, particularly those most vulnerable and with the least voice in society and its decisions. Climate change represents a heightened case of exclusion since those who will suffer first and most belong to three categories largely or entirely bereft of political clout: the global poor (particularly in Africa, Asian mega-deltas and low-lying islands); children and generations not yet born; and other species. While being liberated from fears for personal survival that may prompt desperate acts of self-protection, Christian charity opens the believing community to the suffering of the weak and voiceless and empowers a willingness to enter into their fears and threats and, if necessary, suffer alongside them.

An eschatology that embraces hope for the resurrection of the dead and the renewal of all things simultaneously underscores the preciousness of the created order that is to be redeemed from its bondage to decay and banishes fears of climate catastrophe from the apocalyptic imagination. Relieved from the presumption that we can see what the end of history looks like, the believing community is liberated to respond in freedom to the genuine threats to human society and the community of life represented by climate change without giving in to despair.

A faithful response

Climate change raises a wide range of ethical questions for Christian disciples and broader society. The multifaceted, cumulative sources of the problem, the time lag between emissions and climatic effects, the possibility of dramatic non-linear responses within the system, the supranational effects that rarely correlate geographically or politically with the locations of the primary sources, the association of emission sources with widely desired economic activities, the extreme longevity of the consequences, the invisibility and impersonality of the threat, the complexity of the science and the enormous vested interests at stake: all these factors make a faithful response at personal, communal, societal, national and international levels deeply challenging. And yet the scale and nature of the issue demands responses at each of these levels. Changes to lifestyle without policy changes are as insufficient as policy changes without a widespread change of heart.

At the root of the issue is the question of what it means for human beings and our communities to flourish. Anthropogenic climate change is perhaps the most dramatic manifestation of the unintended consequences of the pursuit of economic growth without regard for the ecological home in which such activity occurs. The equation of material prosperity with human flourishing has not only begun to uncreate the created order, but has also resulted in widespread spiritual poverty. Consumerism, in which we find our identity in what we consume, is consuming not only the planet’s ecological health, but also our souls.

A faithful Christian response to climate change is therefore rooted in repentance and liberation from all such contemporary idolatries. The joyful embrace of a life that is less demanding on the material riches of the planet and more rewarding relationally and spiritually is good news for both the climate and the conscience.

Yet personal attempts to live more simply for the sake of freedom, justice and love require a community of hope to sustain. The Christian church is – or is summoned to be – the kind of community in which such transformation is possible by the power of the Spirit, where life-giving alternatives to an existence dominated by the love of money are explored and affirmed and where hope is nurtured even in the face of death.

At broader levels, Christians may legitimately disagree about how to engage governments and society, and may require expert assistance in the evaluation of various possible policy responses, yet will not be content with collective responses that fail to heed the plight of the most vulnerable and voiceless. Strategies to mitigate the severity and pace of change may include the implementation of technical innovations, but the church will be wary of technological utopias and the lure of obscuring the role of misplaced desires in the equation. Prudent consideration of adaptation measures is also implied by justice and love, as our actions and inactions to date have already ensured a certain level of climate instability. Yet Christians will refuse the false council of pure adaptation, heeding the warning of scientists that unmitigated climate change will likely exceed the ability of natural and human systems to adapt.

The future of our atmosphere is uncertain and threatening to all those who breathe it. God makes no promise that our civilisation will survive, let alone thrive. Yet Christian faith is not dependent upon or subservient to the task of self-preservation. Christians in a changing climate can continue to follow Christ, pouring out our lives in loving serving of neighbour to the glory of God.

Further reading

Intergovernmental Panel on Climate Change, Fourth Assessment Report, 2007. Available online: https://www.ipcc.ch/publications_and_data/publications_and_data_reports.shtml.

Australian Academy of Science, The Science of Climate Change: Questions and Answers (August 2010). Available online: http://www.science.org.au/reports/climatechange2010.pdf.

David Archer. Global Warming: Understanding the Forecast. Oxford: Blackwell, 2007.

Clive Hamilton. Requiem for a Species: Why we resist the truth about climate change. Sydney: Allen and Unwin, 2010.

Michael Northcott. A Moral Climate: The Ethics of Climate Change. London: Darton, Longman and Todd, 2007.

Stefan Skrimshire (ed.). Future Ethics: Climate Change and Apocalyptic Imagination. London: Continuum, 2010.

Nick Spencer and Robert White. Christianity, Climate Change and Sustainable Living. London: SPCK, 2007

—Byron Smith