530 likes | 537 Views
Climate Change, the Built Environment and Plan B Nils Larsson International Initiative for a Sustainable Built Environment 01 March 2018. Climate change overview. Source: The Economist 25 Sep17. IPCC WG II, AR5: Summary for Policymakers. RCP = Representative Concentration Pathway.
E N D
Climate Change, the Built Environment and Plan BNils LarssonInternational Initiative for a Sustainable Built Environment01 March 2018
IPCC WG II, AR5: Summary for Policymakers RCP = Representative Concentration Pathway. RCP 2.6 assumes a GHG peak of 490 ppm before 2100, then declining; RCP 8.5 assumes 1370 GHG emissions by 2100, and rising see http://www.iiasa.ac.at
The built environment is implicated in many sectors of GHG emissions
CO2 emissions have very long-term effects on global temperature and sea level Source: IPCC Source: IPCC AR5
The nightmare scenario: total global carbon content estimated in billions of tonnes Sources: Schuur et al., UNEP, CDIAC, in Climate Safety, Public Interest Research Centre, UK, 2008
An unavoidable factor: 90% of urban growth is taking place in the developing world and these countries want a western standard of living.Urban populations in Africa and Asia will double in the next 20 years and their populations aspire to western standards of living About 2.5 B About 1.1 B UN World Population Prospects: The 2006 Revision and World Urbanization Prospects: The 2007 Revision (Hoornweg)
Specific impacts of high temperatures • Higher temperature increases evaporation rates, which aggravates water shortages; • Generally, higher temperatures leads to more use of mechanical cooling which creates more demand for electricity, which in turn creates more GHG emissions. • Heat waves can cause higher death rates, especially in the older population. The estimated extra mortality in eight European countries from the 2003 heat wave was 34,897 *; • Electricity demand rose significantly because of the intense use of cooling systems, and hydroelectric production was reduced by 19% because of reduced river flow rates, and nuclear production was reduced by 4% because the water temperatures of river cooling water rose above acceptable levels. * J-L. Salagnac, Building Research & Information, July/August 2007
Urban heat islands: Paris, August 4-13, 2003 B. Dousset, ESA user consultation meeting, Athens, June 2007
Urban heat islands Here is graphic proof that vegetation in urban areas helps to reduce overheating. Current index is Beijing is 0.12 ! B. Dousset, ESA user consultation meeting, Athens, June 2007
IPCC WG II, AR5: Summary for Policymakers Remember that averages hide extreme highs and lows WG1 AR5 Fig. SPM-8
Increased wind speeds will cause high levels of damage to small structures Source: Climate Change Risks to Australia's Coast: A First-Pass National Assessment, Department of Climate Change, Government of Australia, 2009
Economic v. insured catastrophe losses 1970-2015 Source: Swiss Re Economic Research & Consulting, 2015, in Investing for Resilience, ClimateWise, University of Cambridge, December 2016
The problem • Climate change has definitely arrived; • Key industry and government leaders have hesitated too long to implement adequate long-term mitigation measures; • Measures that have been implemented tend to be of the no-regrets and painless variety, but these are not sufficient to make the major and rapid reductions that are needed; • If no serious measures are introduced quickly, the probability of serious economic disruption and social unrest is high; • In view of these factors, we believe that regionally-sensitive plans for more rapid action are urgently needed, and we present a number of long-term and short-term proposals along these lines.
What we must do This section was developed by Nils Larsson of iiSBE with substantial contributions from Gregor Herda (UN Habitat), Richard Lorch and Fionn Stevenson (UK), John Shiel (Australia), Stella Bezerra and Roberto Lamberts (Brazil), Teresa Coady, Jean Cinq-Mars, John Crace, Gary Martin and Mark Gorgolewski (Canada), Teresa Parejo-Navajas (Spain), Randa Mahmoud (Egypt), Daniel Charles (France), Ann Edminster and Giancarlo Mangone (USA), Norman Goijberg (Chile), Wynn Cam (Singapore) and Andrea Moro (Italy).
Two principles: We must continue to work on the longer-term issue of reducing emissions, to prevent the problem from worsening; But we must also develop strategies for responding quickly to extreme weather events, which may arrive more quickly than we expect, We need to show a reduction in atmospheric GHG levels by 2020 if we are to have a global temperature increase of less than 2ºC.
What are effective long-term actions to reduce GHG emissions in such a context? We must immediately launch long-term measures to reduce GHG emissions and to develop strategies to adapt to extreme weather events in the future. We must therefore; • ... implement mitigation measures now in view of the long lag time to see reductions in emissions; • … invest in order to avoid staggering costs and drops in asset values later; • … adapt our buildings and infrastructure to cope with future conditions;
Effective short-term actions to deal with extreme weather events We must develop strategies for responding quickly to extreme climate or weather events, which may arrive more quickly than we expect. That means that we need actions to: • … protect infrastructure and building stocks; • … be able to relocate large domestic populations or provide short-term housing for climate refugees from elsewhere; • … be prepared for repair and reconstruction efforts.
First steps A preliminary step: identify regional vulnerabilities and risks: Identify specific vulnerabilities of the subject region to the major effects of climate change. Primary effects will include changes in local climate, ambient temperatures, precipitation and wind regimes, and these may vary greatly depending on the climatic region and exposure. Secondary effects include changes in the frequency of forest fires, riverine or coastal flooding, loss of soil stability, and damage to buildings and infrastructure; These effects may, in turn, lead to disruption of business or educational activities, the relocation or migration of sections of the local population or, in extreme cases, social unrest.
A: Actions requiring a substantial implementation period or continuous action – starting immediately
Proposals for key contingency actions • Assess sustainability performance at the level of neighbourhoods and establish performance targets Based on anticipated future climate change impacts that may affect the local region, develop performance targets and implementation strategies for both long-term and rapid action that can be launched within a five-year period.
Proposals for key contingency actions • Reduce carbon emissions.Introduce policy measures to radically and rapidly cap and reduce carbon emissions linked to the built environment. Such measures have the added benefit of reducing air pollution. Possible measures include carbon taxes, cap and trade or personal allowances. Examples of successful approaches can be found in Tokyo and British Columbia The Tokyo Cap-and-Trade Program (TCTP), implemented in 2010, is an important measure…to achieve Tokyo’s greenhouse gas target…. Data indicate that TCTP has been effective in reducing energy consumption… to meet … emission reduction goals, to introduce new technologies, and to raise awareness and drive behavioural changes for energy demand reduction. .
Proposals for key contingency actions • Reduce carbon emissions:.In 2008, British Columbia implemented the first comprehensive and substantial carbon tax in North America. By 2012, the revenue-neutral tax had reached a level of C$30/t CO2, and covered approximately three-quarters of all greenhouse gas emissions in the province… Empirical and simulation models suggest that the tax has reduced emissions in the province by 5–15%. At the same time, models show that the tax has had negligible effects on aggregate economic performance, though certain emissions-intensive sectors have faced challenges.
Proposals for key contingency actions • Clean energy and renewables .Minimize reliance on fossil fuels for electricity generation, upgrade power grids to accommodate renewable input sources, accelerate the introduction of decentralized renewable power sources, and ensure that feed-in tariff policies do not distort energy markets.
Proposals for key contingency actions • Support development of Synergy Zones.A Synergy Zone is a cluster of buildings located in close proximity that offers energy and emission benefits due to differences in demand, supply or phasing of these; • Thermal surpluses or deficits can be exchanged between buildings; • Greywater surpluses and deficits can also be exchanged; • But the most important advantage is the potential for the direct use of DC power that is collected in PV assemblies on the site or integrated in buildings; • Using DC directly avoids conversion losses to AC of 10% in each direction.
Diverse occupancy profiles provide opportunities • Support development of Synergy Zones.
Support development of Synergy Zones. AC and DC distribution NL-iiSBE, Jan. 2011 Best viewed in slideshow mode
Proposals for key contingency actions • Reduce risks from climate hazards such as flood, winds, drought and forest fires. Prohibit new construction in areas with a high risk of flooding or fire, and ensure that the insurance industry supports efforts to rebuild in less vulnerable locations and to increase resilience of the built environment. .
Proposals for key contingency actions • Mitigate heat island effect Implement steps to reduce ambient temperature increases due to urban heat island effect. Measures can include increasing areas devoted to trees and park areas, higher albedo of building roofs, streets and parking areas; installation of green roofs and vegetated walls, and promotion of effective urban ventilation.
Proposals for key contingency actions • Encourage urban agriculture The availability of small and localized plots of land for urban agriculture will become of increasing importance as the use of transport and private vehicles is discouraged in urban areas, and areas available in surrounding regions for agriculture shrink.
Proposals for key contingency actions • Ensure very high performance of new buildings • limit embodied emissions, • require nearly-zero operating GHG emissions, • limit peak electrical loads, • limit water consumption, • minimizeenvironmental loadings, • maximize indoor environmental quality and service quality, • deliver all this at a low life-cycle cost These traditional performance goals must now be supplemented with measures to improve building resilience against new conditions of extreme wind, precipitation and flooding events, as well as better hot-weather performance.
Proposals for key contingency actions • Limit embodied energy and emissions.Support adoption of environmental product declarations and require estimates of life-cycle and embodied emissions for heavy construction materials in major projects. Systems such as high-performance windows, external shading devices or added insulation or thermal mass, can improve operating performance, but all require an investment of added embodied energy and emissions. Such trade-offs are often overlooked. There is a danger in being bogged down in detailed calculations for minor building components, and it should be recalled that most GHG embodied emissions are related to the use of a small number of heavy materials, such as gravel, sand, cement, steel and glass.
Proposals for key contingency actions • Undertake intensive and deep green renovationWhere substantial performance gains are possible in a large number of residential and non-residential buildings, establish major programs for deep green renovation that result in nearly-zero operating emissions, better hot weather performance, reduced peak electrical loads and water consumption. Because of the variety of existing building types, training for contractors will have to be intensive and extensive. Minimum renovation rates of 5% per year of floor space in OECD regions and 3% per year in other regions have been suggested by Climate Action Tracker. Obviously, these global goals will need adjustment for sub-regional or national variations in the suitability of existing building archetypes, the availability of appropriate equipment and of skilled workers. Intensive training will be required in many locations. See http://climateactiontracker.org
New buildings are a small proportion of the total stock Total building stock Existing buildings Certified buildings New buildings Approximate proportions in the building stock
Proposals for key contingency actions • Support a shift from private to public transport.Support the viability of local public transport and discourage use of private cars through: • Mixed uses to encourage walking and bicycling • Higher urban densities • Location of residential development v. public transport stops • Limitations on on-street and off-street parking for vehicles;
Proposals for key contingency actions • Strengthen equipment and appliance efficiencies Prohibit the sale of appliances and equipment that do not meet high operating efficiency criteria (e.g. "A+++" label in Europe), and ensure the efficient recycling of components.
Proposals for key contingency actions • Limit peak electrical demandRapidly reduce peak loads in electrical networks through rate structures to meet demand and to ensure that existing generating facilities are efficiently used.
Proposals for key contingency actions • Assess and monitor performance, track key indicators and maintain dataEstablish performance targets for a range of building types and ensure that performance assessments for major projects are undertaken prior to completion of the design stage. Ensure that performance assessments take into account possible future climate change impacts that may affect the safety, function or performance of the subject buildings and of its surrounding areas. Such assessment activities should be complemented by performance monitoring systems, with data maintained in public databases to provide building operators and local communities with annual feedback for action on energy, water and occupancy performance.
Proposals for key contingency actions For small urban areas, the EVALOC project in the UK provides a good model for participatory evaluations in six small urban areas that are moving towards low-carbon status. Colours show different rates of CO2 emissions.
Proposals for key contingency actions • Protect critical facilities and infrastructure Ensure that facilities and services of critical importance, such as hospitals, fire and police stations, public transportation systems, food supplies, telecommunications, water and sewage treatment and pumping systems, can remain functional at a basic level of performance under extreme conditions.
Proposals for key contingency actions • Prepare to house relocated populations Identify empty dwellings that may be useful for relocated populations and identify hotels, office buildings, schools and other public-use buildings that may be suitable for rapid conversion to residential uses.
Proposals for key contingency actions • Freeze new development and constructionIn developed countries, except for cases of replacement or planned density increases within existing development zones, impose a freeze on new construction and supporting infrastructure in un-serviced or low-density areas.