Jason King of landscape+urbanism has posted another insightful and topical examination of the implication of the latest IPCC report on global warming and particularly what is means as a landscape architect to be able to do something ..walk the talk or just understand it at least – the extract I have chosen her is relevant to my previous post of becoming CO2+ – bu toy can read the fullest on Jason’s blog here
The background is:
The connection to the science is vital to and expanded knowledge of climate change, as I mentioned in the post on the Foundations of Climate Change Inquiry. One of those foundations mentioned is the work of the Intergovernmental Panel on Climate Change, which is the body of the United Nations focusing on the global science and impacts related to climate change. Their October 2018 IPCC Special Report focuses on “the impacts of global warming of 1.5°C above pre-industrial levels and related global green house gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.”
Likely some of us like to skip all the doom and science stuff and get to what we can do – don’t forget to read Jasons intro though….
The wide array of options for mitigation are collectively referred to as “system transformations”, as I mentioned, interesting as they include a number of landscape-specific ideas. And, based on the dire predictions of our available remaining carbon budget, reductions alone will not suffice to get us to levels that can keep warming at 1.5°C or even 2°C, especially without overshoot. Per section C.2 we require:
“…rapid and far-reaching transitions in energy, land, urban and infrastructure (including transport and buildings), and industrial systems. These system transitions are unprecedented in terms of scale, but not necessarily in terms of speed, and imply deep emissions reductions in all sectors, a wide portfolio of mitigation options and a significant upscaling of investments in those options.”
As I mentioned, efficiency is one aspect, and a combination of new and existing technologies are needed, including “electrification, hydrogen, sustainable bio-based feedstocks, product substitution, and carbon capture, utilization and storage (CCUS)”, to name but a few. I think of the book Drawdown as a good snapshot of many of these strategies and their potential. However, as mentioned, while these are technically proven at a number of scales, large-scale deployment of these is constrained, and often has trade-offs with other strategies.
We also need changes in systems, for instance section C.2.4 mentions urban and infrastructure system transitions, which imply “changes in land and urban planning practices, as well as deeper emissions reductions in transport and buildings…” to get us to these targets. Many of these are not new, but do come with some baggage: “Economic, institutional and socio-cultural barriers may inhibit these urban and infrastructure system transitions, depending on national, regional and local circumstances, capabilities and the availability of capital.”
The final section does present some interesting options, specific to CO2removal, which are collectively referred to as CDR for “carbon dioxide removal” which range in potential. These include:
- afforestation and reforestation
- land restoration and soil carbon sequestration
- bioenergy with carbon capture and storage (BECCS)
- direct air carbon capture and storage (DACCS)
- enhanced weathering and ocean alkanlinization
Two mentioned previously have some huge potential. For instance BECCS can capture up to 5 gigatons of CO2 per year, and afforestation an additional 3.6 gigatons of CO2 per year. As we find out more about the potential we can employ these strategies at larger scales, however there are trade-offs, such as the competition with other land use (for instance agriculture for food production) and the need to protect valuable ecosystem resources. One strategies mentioned is to use multiple, small installations, versus massive projects, to spread out impacts.
Related specifically to landscape systems, the connection to ecosystem services is highlighted with the multi-functional benefits, as mentioned in section C.3.5. The use of Agriculture, Forestry and Other Land Use (AFOLU) measures for CDR, have a number of co-benefits, such as restoration of natural ecosystems providing additional soil carbon sequestration, increased biodiversity, soil quality, and food security, if managed sustainably.