A Changing Climate
Whilst some disasters are immediate, situated, and easily recognisable, the same cannot be said for the ‘slow’ disasters of climate change. Past climate changes were due to natural variations and events. However, recent climate changes are unequivocally due to human activity and are accelerating due to the release of greenhouse gas emissions (GHG) and other activities. As the effects of accelerated global warming grow, the risk of climate-induced displacement through disaster escalates.
According to the Intergovernmental Panel on Climate Change (IPCC), human activities have unequivocally caused global warming. The World Meteorological Organisation reported that the annual average global temperature in 2023 was 1.45 ± 0.12 °C above pre-industrial levels. Continued greenhouse gas (GHG) emissions will further increase warming. Projected GHG emissions make it likely that warming will hit the 1.5°C midpoint in the early 2030s; and possibly in the late 2020’s under the highest emissions scenario. The current emissions trajectory also makes it challenging to constrain warming below 2°C: if current mitigation policies continue, we are headed towards global warming of 3°C over the century, according to the UN Environment Programme.
The underlying drivers of GHG emissions include unsustainable fossil-fuel energy usage, land use practices and patterns of lifestyles, consumption and production across individuals, regions, and countries. Anthropogenic climate change is already causing sea level rise and impacting weather and climate extremes - leading to losses and damage that disproportionately affect vulnerable communities. Global climate projections include intensified global water cycle variability – leading to more severe floods and droughts, global monsoon precipitation and tropical cyclones, extreme variable weather patterns, heatwaves, fire weather, and increased ocean acidification and deoxygenation.
Efforts to reduce carbon emissions, while crucial, will not prevent the ongoing effects of climate change. Cascading and compounding risk scenarios exacerbate existing stressors and limit adaptation options. For instance, the 2019-20 Australian Black Summer bushfires burned 5.8 to 8.1 million hectares, destroyed the habitats of threatened species, destroyed 3,000 houses, and claimed 33 lives. Additionally, 429 deaths and 3230 hospitalisations resulted from cardiovascular or respiratory conditions. The economic toll included health costs estimated at AUD $1.95 billion, insured losses at AUD $2.3 billion, and losses in tourism, hospitality, agriculture and forestry at AUD$3.6 billion.
Climate change risks are becoming increasingly complex and more difficult to manage, with compounding and intersecting climatic and non-climatic risk. For example, biodiversity loss in land, freshwater and ocean systems, decreasing food production and variations in water availability lead to increased risk of food insecurity. This is compounded by competition for land between urban expansion and food production, competition for resources, displaced populations, conflict, and pathogens. Increases in heat-related human mortality and morbidity, food-borne, water-borne, and vector-borne diseases and increased mental health challenges will all place populations at increased risk.