Projected Extreme Heat Stress in Northern Australia and the Implications for Development Policy

ABSTRACT

Heat stress, resulting from elevated heat and absolute humidity associated with climate change, will increasingly occur in the tropics and parts of the mid-latitudes and could threaten the liveability and viability of many regions. Concomitant with predictions of increased heat stress in northern Australia, the Australian Government seeks to boost the population in northern Australia substantially. This paper assesses the heat stress-related wet-bulb temperatures the largest northern centres could experience under Representative Concentration Pathways 4.5 and 8.5 by 2080. The paper finds that substantial population growth could place significant future urban populations at risk from heat stress-related health issues.

KEYWORDS:

• Population growth
• climate change
• heat stress
• wet bulb temperature
• wet bulb globe temperature
• Northern Australia

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Notes

1. RCPs are greenhouse gas concentration trajectories utilised in the Fifth Assessment Report of the Intergovernmental Panel (IPCC) on Climate Change in 2014 as a basis for the report’s findings. According to the IPCC ‘Scenarios without additional efforts to constrain emissions (‘baseline scenarios’) lead to pathways ranging between RCPs 6.0 and 8.5ʹ (Intergovernmental Panel on Climate Change, 2014, p. 8). Current projections for climate change in the coming decades fall somewhere between RCPs 4.5 and 8.5. [Note: Since the original submission of this article, the Sixth Assessment Report has been released with updated modelling and the replacement of RCPs with Shared Socioeconomic Pathways (SSPs). The 2100 temperature projections for SSP2-4.5 and SSP5-8.5 are broadly similar to the equivalent RCPs (approximately 0.2–0.3°C higher) meaning the analysis presented here remains suitable for its intended purpose.]

2. Absolute humidity is a measure of the actual quantity of moisture in the air while ‘relative’ humidity is the quantity of moisture relative to the maximum moisture content of the air at a given dry bulb temperature.

3. https://climatechip.org/excel-wbgt-calculator

Additional information

Funding

The preparation of this paper was part funded by an Australian Research Council, Discovery Project grant [DP190101093].