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  • Writer's pictureAdhish Gurung

What does the climate crisis mean for urban planners?

An interdisciplinary urban planner's impression of the IPCC report on Global warming of 1.5°C


Recently I embarked on the unenviable and thoroughly depressing task of reading the IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. I made it through the technical summary. The report itself is a six-hundred thirty-page mammoth. A comprehensive and thorough analysis of the impact on biodiversity, human settlements, and ecosystems if, and more increasingly when, the average temperature of the earth rises by 1.5°C (more likely between 2-4°C) due to increased carbon emissions in the atmosphere. It paints a bleak picture for many human settlements, particularly low-lying coastal areas, mountainous regions, and the Arctic. Not to mention a mass extinction of biodiversity never before experienced, global crop failures, and decimation of marine and land ecosystems. However, it shares a minuscule glimmer of hope that limiting temperature rise to 1.5°C is possible within the laws of physics and chemistry but requires unprecedented transitions in all aspects of society. Let's unpack those transitions address the consequences of failure to do so.


Catastrophic consequences to a temperature rise of 1.5°C


At this point in time unless you are a climate change denier (a la Amy Coney Barrett) you are well aware of human impact on the climate. Models predict that even under a modest temperature rise of 1.5°C many of our ecosystems will suffer irreperable damage. Most models predict a temperature increase of 4°C by 2100 with cataclysmic repercussions to life on earth. With so much misinformation circulating, let's revisit some of the impacts that 1.5°C will cause since this is the basis of the Paris Agreement.


Observed global temperature change and modeled responses to stylized anthropogenic emission and forcing pathways. Source: IPCC 2018

The first misconception is that people assume an average 1.5°C increase means an additional 1.5°C change in the current temperature of wherever they are located. So instead of being 28°C in sunny California, it will be a toasty 29.5°C. In reality, this means massive fluctuations in temperatures throughout the world, erratic climatic events, and acute temperature increases in vulnerable places such as the Arctic, which is experiencing two to three times warming above the global average and is currently on FIRE.


Climate is linked to our crops, our marine life, our human settlements. These will all experience irreversible damage even under a 1.5°C scenario.

"Of 105,000 species studied, 6% of insects, 8% of plants and 4% of vertebrates are projected to lose over half of their climatically determined geographic range for global warming of 1.5°C"

It simply isn't just bees, orangutans, and coral reefs that are in danger. Regions such as sub-Saharan Africa, Southeast Asia, and Central and South America are projected to have smaller yields of maize, rice, wheat, and potentially other cereal crops. Many vulnerable regions simply will not grow crops again. "Some vulnerable regions, including small islands and Least Developed Countries, are projected to experience high multiple interrelated climate risks even at global warming of 1.5°C". The effects of climate change are anticipated to be disproportionately felt by disadvantaged communities most intensely who have contributed the least amount to carbon emissions. This makes it an environmental justice issue as much as an existential issue.

Impacts and risks for selected natural, managed and human systems. Source: IPCC 2018


What can urbanists do to make an impact?


On your own, probably nothing. This isn't an individual challenge where flying less and going vegan will suddenly reduce carbon emissions at a scale never before witnessed. This is a collective, political, and existential challenge. Urban adaptation is going to require green infrastructure, sustainable land use planning, and sustainable water management. Urban Heat Island effects will be amplified with an acute rise in urban diseases such as Malaria. Small islands and coastal regions will be inundated and a billion people will have to relocate. Heatwaves, heavy precipitation, drought are already observed at higher levels requiring urban planners to modify cities to make them habitable. There is no single answer to reducing emissions to keep the rising temperatures below 1.5°C. However, urban planners are at this time in the most uniquely challenging period facing the greatest rebuild and retool since World War II. With over half of the world's population living in urban areas, urban planners can impact how half the world consume and live.


One of the key transitions is energy. No scenario that shows maintaining temperature rise below or up to 1.5°C is possible with the current usage and dependency on fossil fuel energy. A transition from fossil fuel to renewables (most of which is already available and now affordable) is critical. Understanding energy needs to be an essential component of a planner's curriculum.

"Pathways limiting global warming to 1.5°C with no or limited overshoot would require rapid and far-reaching transitions in energy, land, urban and infrastructure (including transport and buildings), and industrial systems"

The necessity to deeply reduce energy usage in our buildings and increase energy efficiency combined with carefully designed adaptation projects that do not inadvertently raise emissions or increase gender and social inequality is made explicitly clear.


As a researcher from the Global South, one aspect that particularly infuriates me is that the effects of climate change are disproportionately being felt by communities who contributed least to it. Millions of our most vulnerable will be displaced before 2030. Adaptation projects will start to become the primary objective of many cities, occupying urban planners by the thousands. The Report warns us of the compromises planners will make that could have an adverse impact on communities.

"Trade-offs between mitigation and adaptation, when limiting global warming to 1.5°C, such as when bioenergy crops, reforestation or afforestation encroach on land needed for agricultural adaptation, can undermine food security, livelihoods, ecosystem functions and services and other aspects of sustainable development"

The demand is that urban planners will have to deliver symbiotic and comprehensive systems solutions and not just one-off symptoms solutions. The challenge is unprecedented, the work is unrelenting, and the outcome if we fail will be the demise of millions of people either directly by the effects of an unforgiving climate or indirectly through the loss of jobs, food, and shelter. The Report suggests with high confidence that a shift to low emissions, climate resilient infrastructure through evolution of global financial solutions can have significant impact on carbon reductions. This strategy needs to be coupled with massive reforestation and afforestation for carbon capture and storage. Finally, the largest impact can come through politcal and policy changes that enforce "fundamental societal and systemic changes to achieve sustainable development, eradicate poverty and reduce inequalities". This needs to be the top priority for urban planners who now find themselves centrally positioned in the climate crisis debate facing a once in a millenia threat to a habitable planet.


Title images: left from Science News and right from Aleksejs Bergmanis

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