Europe, North America and parts of Asia can expect not just more intense but also longer lasting periods of heat, drought and rain during summer as the planet warms, worsening impacts on health and agriculture. The study, published in journal Nature Climate Change, also shows that limiting global warming to 1.5°C above pre-industrial levels in line with the Paris Agreement would largely avoid these additional impacts.
Heat and rainfall extremes have intensified over the past few decades and this trend is projected to continue with future global warming. A long persistence of extreme events often leads to societal impacts with warm-and-dry conditions severely affecting agriculture and consecutive days of heavy rainfall leading to flooding.
Here we report systematic increases in the persistence of boreal summer weather in a multi-model analysis of a world 2 °C above pre-industrial compared to present-day climate.
Averaged over the Northern Hemisphere mid-latitude land area, the probability of warm periods lasting longer than two weeks is projected to increase by 4% (2–6% full uncertainty range) after removing seasonal-mean warming. Compound dry–warm persistence increases at a similar magnitude on average but regionally up to 20% (11–42%) in eastern North America. The probability of at least seven consecutive days of strong precipitation increases by 26% (15–37%) for the mid-latitudes.
We present evidence that weakening storm track activity contributes to the projected increase in warm and dry persistence. These changes in persistence are largely avoided when warming is limited to 1.5 °C. In conjunction with the projected intensification of heat and rainfall extremes, an increase in persistence can substantially worsen the effects of future weather extremes.
Coastal loss and damage for small islands
This commentary on a paper in Nature Sustainability reviews how the study quantifies the impacts of sea-level rise on small island states and estimates the impacts in terms of cost, land loss and population exposure across all small islands worldwide.
Risks of synchronised low yields are underestimated in climate and crop model projections
This study finds that the jet stream – air currents in the upper atmosphere – can synchronise extreme weather caused by climate change, resulting in crop failures in multiple countries at the same time.
The deployment length of solar radiation modification: an interplay of mitigation, net-negative emissions and climate uncertainty
Here, we investigate the deployment timescales of solar radiation modification and how they are affected by different levels of mitigation, net-negative emissions and climate uncertainty.
Solar radiation modification: a dangerous distraction from required emissions reductions
Investing precious time and resources in this critical decade to explore SRM technologies distracts from the urgent need to step up mitigation efforts to halve emissions by 2030.
Emissions as usual: implications for the Safeguard Mechanism of LNG and coal mine projects
This report examines the implications of committed and proposed developments in the LNG and coal mining sectors for reform of Australia's Safeguard Mechanism.
Only halving emissions by 2030 can minimise risks of crossing cryosphere thresholds
Institutional decarbonisation scenarios evaluated against the Paris Agreement 1.5°C goal
This study analyses six institutional decarbonisation scenarios published between 2020 and mid 2021 (including four from the oil majors and two from the International Energy Agency. It finds that most of the scenarios would be classified as inconsistent with the Paris Agreement as they fail to limit warming to ‘well below 2 ̊C, let alone 1.5 ̊C, and would exceed the 1.5 ̊C warming limit by a significant margin.
Uncertainty in near-term temperature evolution must not obscure assessments of climate mitigation benefits
This work comments on a study by Samset et al. that found the effects of emission mitigation will only be perceived through global temperature with a multi-decadal delay. This paper provides additional context and expresses concerns with the approach.
An emission pathway classification reflecting the Paris Agreement climate objectives
When categorising pathways in line with the Paris Agreement, the focus has been put on the temperature outcome. Here we propose a pathway based on emission reduction objectives that reflect the climate criteria set out in the Paris Agreement.
No time for complacency: without closing the 2030 gap, net zero targets cannot prevent severe climate impacts
Fossil gas: a bridge to nowhere
This report assesses how fast fossil gas power generation must be phased out in different parts of the world to keep the Paris Agreement’s 1.5°C temperature goal in reach.
Managing climate change risks to world heritage using the In Danger List: Griffith climate action beacon policy discussion paper
This paper considers how the World Heritage Convention’s ‘List of World Heritage in Danger’ could be used more effectively for managing sites threatened by climate change or where climate change has already caused significant degradation.