Emission targets for avoiding dangerous climate change

A number of recent studies have found a strong link between peak global warming due to anthropogenic carbon dioxide and cumulative carbon emissions from the start of the industrial revolution. This thesis builds on this work by using a simple climate model to apply the concept of cumulative emissions to emission floors, by comparing cumulative emissions with other types of emissions target, and by extending the work to apply to noncarbon dioxide (CO2) greenhouse gases and short-lived climate forcers (SLCFs). Though peak global warming correlates well with cumulative carbon emissions, the link to emissions over shorter periods or in the years 2020 or 2050 is shown to be weaker. It is also shown that the introduction of emissions floors does not reduce the importance of cumulative emissions, but may make some warming targets unachievable. For pathways that give a most likely warming up to about 4°C, cumulative emissions from pre-industrial times to year 2200 correlate strongly with most likely resultant peak warming in the simple model used, regardless of the type of emissions floor used. The maximum rate of CO2- induced warming is not determined by cumulative emissions but is shown to be limited by the peak rate of CO2 emissions. A simple model of non-CO2 greenhouse gases is also developed and used to investigate SLCFs. It is shown that emissions of SLCFs today have little impact on peak warming, and that delaying near-term reductions in SLCFs would not have a significant impact on peak warming. Only once CO2 emissions are falling do SLCF emissions have a significant impact on peak warming. A global climate policy framework is presented as an example of how the work in this thesis could be used in policy. Future work is also discussed, particularly verification of these results in a more complex model.This thesis is not currently available on ORA

Potential abiotic stress targets for modern genetic manipulation.

Research into crop yield and resilience has underpinned global food security, evident in yields tripling in the past five decades. The challenges that global agriculture now faces are not just to feed 10+ billion people within a generation, but to do so under a harsher, more variable and less predictable climate, and in many cases with less water, more expensive inputs and declining soil quality. The challenges of climate change are not simply to breed for a "hotter drier climate", but to enable resilience to floods and droughts and to frosts and heat waves, possibly even within a single growing season. How well we prepare for the coming decades of climate variability will depend on our ability to modify current practices and innovate with novel breeding methods, and to communicate and work with farming communities to ensure viability and profitability. Here we define how future climates will impact farming systems and growing seasons, thereby identifying the traits and practices needed and including exemplars being implemented and developed. Critically, this review will also consider societal perspectives and public engagement about emerging technologies for climate resilience, with participatory approaches presented as the best approach.Andrew F. Bowerman, Caitlin S. Byrt, Stuart John Roy, Spencer M. Whitney, Jenny C. Mortimer, Rachel A. Ankeny, Matthew Gilliham, Dabing Zhang, Anthony A. Millar, Greg J. Rebetzke, and Barry J. Pogso