IPCC

Climate Report

The impacts of global warming are now simply “irreversible”

With attention fixed on the war raging in Ukraine just days after an invasion by Russia, there’s a greater-than-normal risk that the latest report from the coalition of top scientists on the UN-backed Intergovernmental Panel on Climate Change (IPCC) will go overlooked. But, it must not be overlooked as it contains a dire warning of ‘irreversible’ impacts of global warming.

The second report of the IPCC Sixth Assessment Report series titled “Climate Change 2022: Impacts, Adaptation and Vulnerability” details how climate change is impacting nature, societies and economies, as well as what we can do to adapt in a warming world. It characterizes adaptation measures and makes the consequences of inaction wrenchingly clear. The more than 3,500-page document is rife with devastating details about the toll of rising sea levels, scorching heat and escalating natural disasters.

Here are some of the report’s main conclusions:
‘Widespread’ damage is already occurring
Climate-related impacts are already “widespread” and, in some cases, “irreversible,” according to the IPCC. Heat-related human mortality has risen. Extreme weather events and temperatures have exposed millions of people to food insecurity and malnutrition. Agriculture, tourism and other climate-sensitive sectors are seeing losses. Fisheries are in decline in some regions. Migration tied to climate shifts is rising.

People and other animals are already dying in heatwaves, storms and other disasters fuelled by global warming. Hundreds of plant and animal species have disappeared from local areas, both on land and at sea.

Damage is being compounded when climate impacts coincide, such as heatwaves occurring in areas suffering drought. Some losses; for example, those resulting from the death of coral reefs or the melting of glaciers, are irreversible in our lifetimes.

The report calls for a wholesale revision in how humanity lives alongside nature. Just tweaking our social and economic systems “is not going to get us to a climate-resilient future”, said IPCC report co-author Ed Carr.

We are breaching the limits of adaptation
There is a limit to how much we can adapt; eventually, conditions become so extreme that the associated risks are “intolerable”, the IPCC says.

In many cases, it’s still technically possible to adjust for climate-altered conditions, but barriers such as costs or policies stand in the way. The IPCC calls these “soft” limits to adaptation.

With “hard” limits, there are no clear solutions. Biologically, humans can cope with only so much heat. Low-lying islands will eventually be engulfed by sea level rise. Some plants and animals have already hit hard limits, such as coral reefs that have died in marine heatwaves.

Hard limits increase with each increment of warming, but see a big jump at warming of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels. The planet, having already warmed 1.1°C, is expected to hit that threshold within two decades.

Above 1.5°C warming, people relying on glaciers and snowmelt for freshwater will face acute shortages. At 2°C, important food crops won’t grow in many places. And if we overshoot and spend a few decades above 1.5°C warming, many impacts will be irreversible.

Rich countries that are most responsible for carbon-dioxide pollution have the most resources to prepare for its effects, whether or not they choose to do so. Poorer countries with little to no responsibility for climate change face the brunt of the assault — and aren’t receiving promised help from the developed world.

Nature is in big trouble
Every world region faces a high risk of more species losses and extinctions. At 1.5°C warming, scientists expect 3-14% of the world’s species on land could vanish.

Most at risk are coastal species that face future sea level rise, as well as those dependent on seasonal river flows that will be disrupted by drought or by earlier melting of glaciers upriver. Plants and animals that can’t easily move to more hospitable areas are also at high risk.
The report underlines the need to conserve 30% to 50% of the Earth’s land, freshwater and ocean areas – echoing the 30% goal of the UN’s Convention on Biodiversity.

Humans and society will struggle, too
Aside from the public health risks from heatwaves and other weather extremes, there is also a rising risk of disease spread through spoiled food, tainted water or pathogen-carrying insects such as mosquitoes.

In some communities, particularly the poor and vulnerable, malnutrition is increasing. Food production could be compromised by rising seas and disruptive weather, along with poorer soil quality and reduced pollination.

At the same time, climate-linked weather extremes are also disrupting health services and adding to mental health stress, the report says.

We’re running out of time
The report urges people to get ready now for a warmer world. The weather extremes and other climate impacts are happening faster than earlier reports had anticipated.

“Any further delay… will miss a brief and rapidly closing window of opportunity to secure a liveable and sustainable future for all,” the IPCC concludes.

Communities need to be bolstering infrastructure and rethinking their cities to deal with issues such as heat, flood risk or water availability. Efforts that improve liveability while also reducing greenhouse gas emissions are “more urgent than previously thought,” the report says. Actions that prioritize equity and justice, including tackling gender or income inequalities, have better overall outcomes, it says.

While there has been limited progress – at least 170 countries now mention adaptation in their climate plans – most of the world is lagging.

The clock is ticking
Scientists have a word that describes what happens if nations miss their pollution limits and the world heats up past 1.5°C: “overshoot.” Implicit in this idea is that by using nature or technology to draw down greenhouse-gas levels, people can return the temperature back below the limit. The report warns that even if nations are able to do that, there will still be “additional severe risks,” some of which are “irreversible” compared to scenarios without overshoot. Up to 14% of land-based animal species are at risk of extinction once the 1.5°C threshold is passed, the IPCC warned.

This fact informs the physical limitation to climate adaptation and shapes the IPCC’s guidance to reduce emissions as quickly as possible. Cuts today are much more valuable than the same cuts in five or 10 years.

What’s needed beyond cutting emissions
The world needs to reduce carbon dioxide emissions to zero by mid-century and halve 2010 levels by 2030, the IPCC reported in 2018.

But since some further warming is unavoidable, nations’ preparedness matters a lot. Effective adaptation measures are critical. The problem is that efforts so far tend to be fragmented and short-term, according to the IPCC. Plus, adaptation efforts are often underfunded. And as warming increases, their effectiveness will go down.

Analysis
Perhaps, the most crucial part of the report is its ‘Summary for policymakers’ that the IPCC reviewed in detail. This is a 40-page gist of years of scientific research that highlights the dangers of climate change resulting in species extinction and the near-collapse of the ecosystem. This environmental degradation is also resulting in extreme weather conditions and new types of diseases. Then there is the question of rapidly declining fresh-water resources including lakes and ponds that are drying up.

Reduced water supplies and contamination in soil badly affect crop yields that are much lower in quality and quantity now in many parts of the world especially in developing countries. This reduction is a direct corollary of global heating across continents. To compound the problem, there are unprecedented floods that turn out to be harmful for crops and soil and also result in increased waterlogging in the affected areas. On the other extreme are wildfires that devour thousands of kilometres of land and burn standing crops and forests without discrimination. These cascades of floods and heatwaves and wildfires have been wreaking havoc year after year in the past couple of decades. But still there is a strong lobby that is hitherto in a state of denial. Now, the new report has put these facts in a brighter light that will be hard to ignore even by diehard skeptics.

With this report, there is a pretty strong case for accelerating efforts to fight carbon pollution that is a driving force behind climate change. Of course, there are already many other devastating consequences that can no longer be reversed and there is a need to devise a strategy for ‘adaptation’. For a country such as Pakistan, though successive governments have been promoting their agendas to tackle climate change, there is a dire need to accelerate such efforts.

The writer is an electrical engineer.