There are many reports based on scientific research that talk about the long-term impacts of climate change — such as rising levels of greenhouse gases, temperatures and sea levels — by the year 2100. The Paris Agreement, for example, requires us to limit warming to under 2.0 degrees Celsius above pre-industrial levels by the end of the century.
Every few years since 1990, we have evaluated our progress through the Intergovernmental Panel on Climate Change’s (IPCC) scientific assessment reports and related special reports. IPCC reports assess existing research to show us where we are and what we need to do before 2100 to meet our goals, and what could happen if we don’t.
The recently published United Nations assessment of Nationally Determined Contributions (NDCs) warns that current promises from governments set us up for a very dangerous 2.7 degrees Celsius warming by 2100: this means unprecedented fires, storms, droughts, floods and heat, and profound land and aquatic ecosystem change.
While some climate projections do look past 2100, these longer-term projections aren’t being factored into mainstream climate adaptation and environmental decision-making today. This is surprising because people born now will only be in their 70s by 2100. What will the world look like for their children and grandchildren?
In this context, researchers from Canadian McGill University, and others from British universities, conducted a new scientific study recently published in the “Global Change Biology” journal to examine the effects of climate change after the end of the current century.
According to a statement published on the McGill University website, the researchers tested the predictions of 3 global climate simulation models, up to the year 2500. These models are based on different scenarios of changing greenhouse gas concentrations in the atmosphere, one of which is consistent with the goal of the Paris Agreement, which states that no more than Global warming of two degrees Celsius by the end of this century.
They also modeled the distribution of vegetation cover, heat stress, and growing conditions for plants of today’s major crops, to get a sense of the kind of environmental challenges that today’s children and their grandchildren may have to adapt from the 22nd century onward.
To depict what the world might look like under the most extreme warming scenarios compared to what we have experienced so far, the researchers used the results of the simulations to produce 9 paintings of 3 major natural regions (the Amazon, the Midwest of the United States and the Indian subcontinent) depicting their landscape as it was in 1500, What it was last year, and what it will be in 2500.
The top painting is based on pre-colonisation Indigenous cities and communities with buildings and a diverse maize-based agriculture. The second is the same area today, with a grain monoculture and large harvesters. The last image, however, shows agricultural adaptation to a hot and humid subtropical climate, with imagined subtropical agroforestry based on oil palms and arid zone succulents. The crops are tended by AI drones, with a reduced human presence.
The top image shows a traditional pre-contact Indigenous village (1500 CE) with access to the river and crops planted in the rainforest. The middle image is a present-day landscape. The bottom image considers the year 2500 and shows a barren landscape and low water level resulting from vegetation decline, with sparse or degraded infrastructure and minimal human activity.
The Indian subcontinent:
The top image is a busy agrarian village scene of rice planting, livestock use, and social life. The second is a present-day scene showing the mix of traditional rice farming and modern infrastructure present in many areas of the Global South. The bottom image shows a future of heat-adaptive technologies including robotic agriculture and green buildings with minimal human presence due to the need for personal protective equipment.
Radical climate change
The study authors found that average global temperatures will continue to increase beyond 2100, under low and medium mitigation scenarios – which do not meet the Paris Agreement goal to limit global warming to well below 2 degrees Celsius – vegetation and the best crop-growing areas may move towards the poles.
The area suitable for some crops would also be reduced. Places with long histories of cultural and ecosystem richness, like the Amazon Basin, may become barren.
The Midwest regions of the United States, known for their temperate climate, will experience agricultural adaptation to a hot and humid subtropical climate, and may be dominated by subtropical agricultural forests based on palm trees.
Places, known for thousands of years for their rich and diverse ecosystems, such as the Amazon Basin, may become barren and devoid of life as the water level in water bodies decreases as a result of deteriorating vegetation cover.
The simulation results also showed that the heat stress may reach, after 5 centuries from now, to levels that are fatal to humans in the currently densely populated tropical regions, such as the Indian subcontinent.
These areas may become uninhabitable even under the Paris Agreement-compliant mitigation scenario, requiring the development of new technologies to adapt to the heat including mechanized farming and green buildings.
How do we avoid disaster?
The period during the past 5 centuries witnessed many great transformations such as colonialism and the industrial revolution, the birth of modern states and institutions, and the excessive use of fossil fuels and what is associated with it from a rise in global temperatures.
“We need to envision the Earth our children and grandchildren may face, and what we can do now to make it just and liveable for them,” says Christopher Lyon, formerly of University of Leeds and now a Postdoctoral Researcher at McGill University. “If we fail to meet the Paris Agreement goals, and emissions keep rising, many places in the world will dramatically change.”
The study’s authors argue that the only option left for humanity is to urgently reduce emissions, while continuing to adapt to inescapable warming as a result of continuing emissions until now.