Climate change impacts

Flooded field

Work Package B: Climate change impacts

Expected impacts under different emissions pathways, and how adaptation might reduce these.
Lead researchers:
Nigel Arnell
Walker Institute
Rachel Warren
Tyndall Centre

Summary

Work package B focuses on the future global and regional impacts of climate change on humans and ecosystems under different levels and rates of climate change; it will also examine the impacts avoided by the emissions pathways produced by AVOID Work Package A. It uses existing impacts models, and will develop indicators of impact with stakeholder communities. In general it will focus on a time period to 2100. Our team includes researchers with expertise on agricultural systems, coastal systems, ecosystems and biodiversity, water resources, human health and economics. We will project impacts upon water availability, coastal flood risk, river flood risk, extreme weather events, crop productivity, crop suitability, ocean acidification, fisheries, heating and cooling demand, biodiversity and economic growth. An important aspect of the work will be to separate impacts due to climate change from impacts resulting from socioeconomic change. Where the information exists, the effects of adaptation on these impacts will be assessed.


What do we already know?

We know that as climate changes, impacts on both humans and ecosystems increase and that reducing the rate of increase in emissions reduces the impacts of climate change. Precise projection of the future levels of impacts is not feasible, but ranges of potential impacts can be estimated, and this will be the methodology that will be followed in this work package. Some climate change impacts, or loss in the land area that is climatically suitable for particular species to live, are independent of socioeconomic changes. However, many other impacts, such as changes in water stress, risks of hunger and so on are dependent on the growth of human population and the level and type of socioeconomic development. Therefore, where researchers have estimated climate change impacts in the past, different estimates of impacts have been produced because of different assumptions about socioeconomic change.

What will this research achieve?

The research will provide information about the climate change impacts associated with different climate change futures and emissions under different future socioeconomic scenarios. A great many studies have over the years compared climate change impacts under different climate scenarios, but virtually all of these have used different socio-economic scenarios for each climate scenario. This assumed a 1:1 relationship between population, economic growth and climate change. Whilst this is internally consistent, we now know that a range of values of greenhouse gas emissions is consistent with any given socioeconomic pathway. More recently, a few studies have begun assessing the impacts associated with different combinations of climate changes and socioeconomic changes, and that will be the focus of this research.

What is the policy relevance?

The research will help policy makers to answer the AVOID question ‘what level of climate change might be considered dangerous’? This is important because Article 2 of the United Nations Framework Convention on Climate Change states that the ultimate aim of the Convention is the “stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner” (UN, 1992). In other words, the aim of global climate policy is to seek to reduce emissions in order to prevent dangerous anthropogenic interference in the climate system. The research itself does not assess levels of danger, but provides information about climate change impacts in a variety of metrics that may be used by policy makers to make their own judgement about what they consider to be dangerous anthropogenic interference.


Research area description and outputs

B1. Post-IPCC assessment of climate impacts using existing scenarios
The IPCC fifth assessment presented new results on climate impacts. The first part of this deliverable will summarise these advances and provide an update to any major new literature that has been produced on climate impacts since the IPCC cut-off date for accepting new information (advances in understanding: View report). The second phase of this work will provide a quantitative reanalysis of existing model results for impacts under the IPCC Representative Concentration Pathway (RCP) scenarios View report. By focusing on this single set of scenarios it will make the impacts easier to interpret, compare and communicate (reanalysis of model projections: due Jan 2015). The final phase of this work will provide a literature review on the effectiveness of adaptation in avoiding climate damages (the effectiveness of adaptation: View report)
B2. Socio-economic climate impacts under new scenarios
In phase one we will produce initial estimates of socio-economic impacts of climate change under the new emissions pathways estimated by AVOID 2. This will result in the production of a report and a first-look set of impact numbers which have been made using a simple methodological approach known as damage functions. The second phase will continue this work to produce improved estimates of socio-economic impacts, delivering a report and set of impact numbers using a more complex and defensible method (View policy card). The final phase of this work will calculate the socio-economic impacts of any new emissions pathways proposed at COP21 ( View report).
B3. Assessment of regional climate impacts
AVOID 2 will aim to host two workshops on regional impacts involving participation of local experts. TBC

Peer reviewed publications

Any peer reviewed publications linked to this work package will appear here.