Publications

Increasing high temperatures due to climate change are exacerbated by urban heat island effects, resulting in a range of human health and economic impacts. The green and blue infrastructure (GBI) in cities that underpins nature-based solutions (NBS) can help alleviate hot-day temperatures. In this study we bring together multiple data sources to evaluate the cooling benefit provided by urban GBI in terms of avoided losses in labour productivity, for eleven City Regions in Great Britain, over a ten-year period. We defined the urban extent to include the green (woodland, grassland and parks, gardens) and blue (rivers and canals, lakes and ponds) features within cities, and derived aggregate cooling factors for urban areas in each City Region, applying additional cooling factors to buffer zones around larger GBI features. We collated gridded meteorology data to assess the number of hot-days exceeding 28 °C Wet Bulb Globe Temperature in each City Region over the period 2008-2017, and applied response functions to evaluate loss of worker productivity for ten economic sectors. For the GBI features (aggregated adjacent features >200m2), gardens make up the biggest component (26% of urban extent) closely followed by grassland and parks (24%), with woodland at 6%. The aggregate cooling factor of GBI ranged from 0.64 – 0.89 °C across the eleven City Regions. The economic benefit of cooling was greatest for London, due to its greater exposure to hot days, and its greater contribution to the economy than other City Regions. In the hottest year of 2015, the cooling benefit in London was £13.97 m. The cooling benefit varied considerably from one year to the next, depending on meteorology, and will increase under climate change.

This report assesses the current knowledge of surface water acidification and its effects on aquatic biota in eastern Canada. We used a critical appraisal of recent research to draw answers to the important questions. What are the size, location, and current chemical condition of aquatic resources in eastern Canada that are thought to be vulnerable to acidic deposition. What are the extent and magnitude of chemical changes in surface waters of eastern Canada that can be attributed to acidic deposition. What evidence exists to support the hypothesis that biological changes in surface waters in eastern Canada have resulted from chemical changes associated with acidic deposition. How many aquatic systems in eastern Canada will become acidic at various levels of acidic deposition and within what length of time. What is the rate at which lake chemistry and aquatic biota improve when deposition is reduced. The aquatic resources evaluated in this assessment are in that area of Canada east of the Ontario-Manitoba border and south of 52/degree/N, excluding the Great Lakes, and encompassing part or all of the provinces of Ontario, Quebec, Newfoundland, Labrador, New Brunswick, and Nova Scotia. 202 refs., 19 figs., 7 tabs.

Subtitle: TT Club's director of global risk assessment, Laurence Jones, suggests ways for port operators to minimise accidents and improve performance.

Whereas much is known of the short‐term growth response to elevated atmospheric CO 2 concentrations, [CO 2 ] elev , there is relatively little information on how the response of native species is modified by temperature, despite the fact that an increase in global mean temperature is expected to accompany the rise in [CO 2 ]. In this study, five functionally related annual native species were exposed to different combinations of ambient and elevated [CO 2 ] and temperatures in order to assess their response in terms of growth and allometry. Fast‐growing annuals were selected for the study because their growth responses could be assessed over a major portion of the plant's life cycle and in as short a period as 8 wk. Plants were grown in eight hemi‐spherical glasshouses, programmed to track outside ambient conditions and provide a replicated experimental design. Treatments comprised (i) current ambient [CO 2 ] and temperature, (ii) elevated [CO 2 ] (ambient+34 kPa), and ambient temperature (iii) ambient [CO 2 ] and elevated temperature (ambient+3°C) and (iv) elevated [CO 2 ] and elevated temperature (T°C elev ). All five species responded positively to [CO 2 ] elev , although the response was statistically significant for only one, Poa annua L. Averaged over all five species, [CO 2 ] elev increased total plant biomass by 25% ( P =0·005) at 56 d, reflecting a proportionally greater increase in leaf and stem mass relative to root weight. Elevated [CO 2 ] had no effect on leaf area, either at the individual species level or overall. Elevated T°C, by contrast, had little effect on shoot growth but increased root mass on average by 43% and leaf area by 22%. Few interactions between elevated [CO 2 ] and T°C were observed, with the CO 2 response generally greater at elevated than ambient T°C. Both [CO 2 ] elev and T°C elev resulted in a transient increase in relative growth rate, ( rgr ), during the first 14 d exposure and a 3°C increase in temperature had no effect on the duration of the response. CO 2 stimulation of growth operated through a sustained increase in net assimilation rate. ( nar ), although the potential benefit to rgr was offset by a concurrent decline in leaf area ratio ( lar ), as a result of a decrease in leaf area per unit leaf mass ( sla ). The response to T°C elev was generally opposite of that to [CO 2 ] elev . For example, T°C elev increased lar through an increase in sla and this, rather than any effect on nar , was the major factor responsible for the stimulation of rgr . Allometric analysis of CO 2 effects revealed that changes in allocation observed at individual harvests were due solely to changes associated with plant size. Elevated T°C, by contrast, had a direct effect on allocation patterns to leaves, with an increase in leaf area expansion relative to whole plant mass during the initial stages of growth and subsequent increased allocation of biomass away from leaves to other regions of the plant. No change in the allometric relation between roots and shoots were observed at either elevated [CO 2 ] or T°C. We conclude, therefore, that allocation of biomass and morphological characteristics such as sla , are relatively insensitive to [CO 2 ], at least when analysed at the whole‐plant level, and where changes have been observed, these are the product of comparing plants of the same age but different size.