The greenhouse effect
Climate change has become a considerable concern for humanity during this anthropocentric age. Scientists believe that the rate of global warming and climate change varies directly with the increase in the concentration of greenhouse gases, particularly carbon dioxide. The Greenhouse gases trap heat and make the planet warmer. Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years. The largest source of greenhouse gas emissions from human activities is from burning fossil fuels for electricity, heat and transportation. Carbon dioxide enters the atmosphere through burning fossil fuels (coal, natural gas, and oil), solid waste, trees and other biological materials, and also as a result of certain chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere when it is absorbed by plants as part of the biological carbon cycle.
Releases carbon dioxide
Emissions or confiscation of CO2, as well as emissions of CH4 and N2O can occur from management of lands in their current use or as lands are converted to other land uses. Carbon dioxide is exchanged between the atmosphere and the plants and soils on land. The cropland is converted into grassland likewise the lands are cultivated for crops or as forests grow. In addition, using biological feed stocks such as energy crops or wood as building materials can lead to emissions.
The Pakistan scenario
Pakistan’s GHG profile is dominated by emissions from the energy and agriculture sectors, whose combined emissions total 87% of national GHG emissions. According to the World Resources Institute’s Climate Analysis Indicator Tool (WRI CAIT), energy contributes 46% of Pakistan’s total annual GHG emissions, of which 26% is attributed to electricity consumption, 25% to manufacturing, 23% to transportation and the remaining 25% to other energy subsectors. Agriculture accounts for 41% of total GHG emissions, of which enteric fermentation is the primary contributor (46%). The land use change and forestry (LUCF) sector contributes 6%, dominated almost entirely by changes in forest land.1 Industrial processes (IP) and waste contribute 5% and 2%, respectively
Impact of construction sector
Urbanization is happening at a higher rate in this era than in any other generation. It was reported that the building sector play sacritical role in the emission of carbondioxide (CO2) in to the atmosphere. Construction of buildings, operation, and utilization of the built environment has led to emissions of a large number of CO2 into the ambient air. Various issues and challenges a rise from the building sector in reducing CO2 emissions. The exploitation of non-renewable energy resources, poor building design, and lack of sustainability consideration in urbanization has been holding back CO2 emission mitigation measures in the building sector. Therefore, CO2 emission mitigation plans and schemes are necessary alongside standardized frameworks and guidelines. The strategies to reduce CO2 in the building sector are enforcing standards and policy, conducting impact assessment, adopting low carbon technology, and restricting energy utilization. All stakeholders must play their roles efficiently to reduce CO2 emissions and aid in the fight against climate change.
Together, building and construction are responsible for 39% of all carbon emissions in the world. With operational emissions (from energy used to heat, cool and light buildings) accounting for 28%. The remaining 11% comes from embodied carbon emissions, or ‘upfront’ carbon that is associated with materials and construction processes throughout the whole building lifecycle.
The role of world green building council
The WGBC is looking forward to fully decarbonize the construction sector by eliminating both operational and embodied carbon emissions.
The World GBC has issued a bold new vision for how buildings and infrastructure around the world can reach 40% less embodied carbon emissions by 2030, and achieve 100% net zero emissions buildings by 2050. This ambitious goal alongside solutions to accelerate immediate action by the entire building and construction value chain. It is endorsed by representatives from developers and construction companies, financial institutions, government, as well as industry representatives from concrete, steel and timber etc. The new construction is expected to double the worlds building stock by 2060 causing an increase in the carbon emissions occurring right now. Therefore, it is the call of the day to have coordinated actions from across the sector to dramatically change the way buildings are designed, built, used and deconstructed.
The transition towards mainstream net zero carbon standards requires immediate action to achieve greater awareness, innovation, improved processes to calculate, track and report embodied carbon, voluntary reduction targets from industry and roll out of new legislation at city, national and regional level. Approaches such as maximizing the use of existing assets, promoting renovation instead of demolition and seeking new circular business models that reduce reliance on carbon intensive raw materials are also needed.
Businesses involved in design and delivery have already committed to ambitious individual or national decarburization strategies. Materials suppliers are also taking a leading role. Leading cement manufacturing company Heidelberg Cement is planning to develop carbon neutral products by 2050.Cities have also been instrumental in pushing for new innovations and approaches. Oslo, Norway, has a commitment to fossil free construction sites. Vancouver, Canada, has mandated that embodied carbon be reduced in new buildings by 40% by 2030, as part of its climate emergency response, demonstrating the type of regulatory frameworks that can drive market change.
The future ahead
The majority of the world’s population live in cities, projected to rise to 70% by 2050. As cities continue to grow, and temperatures continue to rise dangerously, it has never been more important for the buildings and construction sector to be leading the way on climate action. Because the sector is responsible for such a large chunk of global emissions, it means there is huge potential for reduction. Tackling whole life carbon and achieving circularity in the construction sector is the key to a carbon neutral world.
The time has come to make informed decisions on sustainable consumption. Choosing a sustainable consumption pattern is akin to buying a health insurance for ourselves and the planet because it leads to a sustainable future for all. I see both purpose and wisdom in manufacturing and buying low carbon footprint products by every single entity/person on this planet to overthrow the business-as-usual and adopt the business-as-unusual.
The building sector plays a significant part in the emissions of CO2 globally. The tremendous production and release of CO2 have led to severe consequences and repercussions contributing to climate change. The adverse effects of the non-sustainable built environment have not only put a strain on the environment but also have affected humanity. The strategies to reduce CO2 in the building sector are enforcing standards and policy, conducting impact assessment, adopting low carbon technology, and restricting energy utilization. If we continue with the current approach for the building sector, it will be too late to rectify the mistakes of our predecessors. The future of sustainable cities and communities will remain uncertain, and we might fail to achieve global sustainable development goals. The building sector must be given enough attention and care to reduce the rate of CO2 emissions. A comprehensive and thorough analysis is necessary to study the CO2 emission mitigation measures in the building sector, and global organizations must come up with a holistic framework to tackle the issue. For a more sustainable future, it is crucial to implement drastic actions and measures to reduce CO2 emissions to aid the fight in combating climate change.