There is much new evidence of stratospheric intrusions of smoke from intense pyro-cumulonimbus (pyroCb) events from wildfires. These events appear to be increasing in frequency, intensity and plume height in both the northern and southern hemispheres. The impacts of smoke aerosol on climate may be disproportionately larger than volcanic aerosols that are sporadically injected into the stratosphere because i) they strongly absorb sunlight which may influence stratospheric dynamics and ii) their surface characteristics may enhance their role in heterogeneous chemistry and ozone depletion. Given that the record persistent Antarctic ozone hole and record Arctic ozone depletion of 2020 were preceded by unprecedented wildfires, there is an urgent need to understand their role in the climate system. In the northern hemisphere, the strongest stratospheric smoke events have occurred over the past five years. In 2017, a range of remote sensing observations showed that smoke from the Pacific Northwest event (PNE) persisted at 18-22 km altitude for over 5 months. In 2019-2020, stratospheric aerosol loading was anomalously high owing to sulfate and ash from the Raikoke eruption but there is evidence of a possible significant contribution from smoke from the August 2019 Siberian wildfires (SIB). Record halogen-catalysed Arctic ozone depletion was observed in spring of 2020 with a strong Arctic polar vortex cold enough for polar stratospheric clouds (PSCs) to form until well until springtime. Research has suggested that, in the absence of the Montreal Protocol which has reduced humanity's emissions of ozone depleting substances (ODSs), we would have had a northern hemisphere ozone hole, similar to that of the Antarctic. In the southern hemisphere, the January 2020 Australian 'Black Summer' (ABS) wildfires were unprecedented in scale and intensity with millions of tonnes of smoke aerosol and associated gases being injected into the upper troposphere and lower stratosphere. Initial injection altitudes reached 16 km and the smoke eventually reached altitudes of up to 36 km (three times higher than the operating altitude of commercial trans-Atlantic jet aircraft. The ascent to remarkably high altitudes resulted from the self-lofting caused by the presence of black carbon (BC) within smoke which absorbs sunlight and heats the air surrounding it. Just like a hot air-balloon, this absorption of sunlight causes the smoke and the surrounding air to rise. Significantly, it appears that this single event caused the largest global mean stratospheric temperature perturbation for three decades. The Antarctic ozone hole in 2020 was extremely deep and persistent, with record low polar stratospheric temperatures and a strong polar vortex. Several chemical fingerprints determined from satellite observations that suggest that the severe ozone depletion in the Arctic, and the record ozone hole in the Antarctic are linked to these wildfire events. This becomes even more worrying when one considers that wildfire frequency, intensity, and plume altitude are all forecast to increase under future global warming scenarios. It could be postulated that all of the hard work that has been performed very successfully under the Montreal Protocol might be undone not through lack of adherence to ODS reductions, but through global warming. If an ozone hole opens up over the northern hemisphere, this could pose a further existential threat to the delicate ecosystem balance that humanity relies upon. Similarly, the dynamical impacts of absorbing aerosols in the stratosphere may directly impact the Earth's surface climate: an enhanced positive phase of the North Atlantic Oscillation has been modelled in idealised studies which could lead to enhanced flooding in northern Europe and potentially devastating drought over the Iberian Peninsula. It is therefore critical to include these factors and feedbacks in global climate simulations at the earliest opportunity.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

The environment that an individual experiences during growth and development has profound implications for the future health and fitness of that individual during adulthood. In species that provide parental care offspring are usually reared together in broods, so close relations often provide the social environment in which growth and development takes place. However, because parental care is costly to parents (in time and energy), and availability of environmental resources essential for growth and development of young varies unpredictably, offspring demand for food and other resources often exceeds parental supply. As a consequence there may be conflicts of interest among family members over the supply of these parental resources (parental investment; PI), which affects the amount of resources available to individual offspring. The consequences of such conflicts within families can be pervasive, and have important effects for the diversity and evolution of life-history traits and behaviours such as growth rates, clutch size, sexual attractiveness and begging behaviour. The amount of resources available to individual offspring depends upon the amount of conflict, which is determined by the relatedness of family members and the availability of key resources in the environment. However, although the importance of within-family conflicts for growth, development and fitness is increasingly being recognised, very little is known about the mechanisms that underpin such conflicts, or the interrelationships between resource availability, conflict over these resources and the mechanisms that determine the costs and consequences of conflict. Previous work on zebra finches by the author showed that, although receiving less food, offspring reared under conditions of higher within-family conflict had faster growth compared to siblings reared under lower levels of conflict. As a result these offspring were less attractive as adults, indicating a substantial costs of rapid growth and of family conflict. These costs are most probably a consequence of increased oxidative stress, which occurs when high levels of free radicals, which are by-products of normal metabolic processes, cause damage to various cell components. Antioxidants provide protection against the damaging effects of free radicals. An important component of total antioxidant defence is provided by fat-soluble antioxidants, such as carotenoids and vitamin E, which are derived from the diet. The interaction between dietary availability of antioxidants and within-family conflicts has not previously been considered, but is likely to be important as variation in antioxidant availability determines the trade-off between self-maintenance and investment in growth and reproduction, and hence fitness. This project plans to use brood size manipulations, hand-rearing and parent removal experiments and cross-fostering to tease apart the effects of sexual conflict and sibling competition on growth and fitness of offspring, examine the cost basis of growth through the measurement of oxidative stress and manipulation of dietary antioxidant availability, and establish the behavioural mechanisms that underlie the allocation of PI in relation to the social and environmental context in which they are operating. The work integrates nutrition, reproductive ecophysiology and environmental uncertainty with behavioural ecology in examining the costs and consequences of variation in social and environmental effects early in life on adult health and fitness. If funded, the project would be conducted at the Institute of Biological and Life Sciences at the University of Glasgow, using zebra finches Taeniopygia guttata as a model species.

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.