Glaciers are common theme in new UN climate report

Glaciers are common theme in new UN climate report

Glacier appears in many chapters and chapters latest report From the Intergovernmental Panel on Climate Change (IPCC), Report of Working Group II entitled IPCC Sixth Assessment. Published on February 28, it provides detailed observations of historical and recent changes, as well as projections of future changes under different levels of greenhouse gas emissions and warming. This report discusses global and region-specific glaciers. It shows how glaciers are linked to many ecosystems as well as economic and social systems, including adaptive responses and constraints to such responses, and between glacial retreat and conflict.

Physical changes and their effects on people and ecosystems

The report’s most enduring discussion of glaciers can be found in cross-chapter paper 5, simply titled mountains. These biome-focused, cross-chapter papers are a new feature of this working group report, reflecting their emphasis on the interaction of ecosystems with the world’s climate system and the importance of ecosystem-based adaptation in addressing climate risks. Closely.

This mountains The paper discusses the loss of glacier mass as an effect of climate change in mountains, which is attributable to human influence, noting that recent research has shown that this retreat is significantly faster than the levels described in earlier IPCC reports on the subject. , 2019 Special Report on the Ocean and Cryosphere. It confidently states that even with 1.5°C of warming, many low-elevation and small glaciers around the world would lose more than half their mass. It shows important differences between lower and higher rates of greenhouse gas emissions in the coming decades, and between the levels of warming associated with them. These projections are strong enough to say with moderate confidence that low-emission scenarios would retain about half of the current ice volume in low- and mid-latitude mountain regions, while higher levels would result in losses ranging from two-thirds to more than 90 percent.

The cross-chapter paper argues with high confidence that these changes have had severe observable consequences for human and natural systems in many different regions of the world.

Pipes used to transport water from high-altitude glaciers to villages in Pakistan’s Hunza Valley. CEDIT: Zainab Khalid

It highlights the impact of these changes on the mountain water cycle, including the timing and level of streams. It noted that both terrestrial and aquatic ecosystems were affected.Pioneer species can Colonize rock and gravel areas previously covered by ice, allowing new ecological communities to form, while some fish Negative impact By varying the amount of water, temperature, chemical composition and sediment load. Some human systems are also affected: The impact on hydropower is complex, as water supplies in some areas temporarily increase as glaciers shrink rapidly, but declines are found once most of the glaciers are gone – something that some areas face Challenging transitions have been faced, and nearly all of them will be reached in this century.

Glacier retreat may affect food security in regions of Asia and South America where farming communities depend on irrigation, although this report notes that comprehensive studies linking changing river flows, water management, irrigation technologies and interactions between different users are relatively Less watershed-specific groups. For example, meltwater from glaciers is an important source of water for irrigation, but water is also required by hydropower facilities and tourism businesses, adding to complex management issues that have so far been understudied.

The list of impacts is long: The cross-chapter paper points to evidence that mental health problems stem from anxiety and grief over glacier loss, although this evidence has so far been limited. For others, the glacier’s disappearance is an opportunity as a “last tourist opportunity” draws tourists eager to see the glacier before it disappears to New Zealand and the Alps.

Climate Change, Glaciers and Conflict

cross chapter mountains This article provides examples of glaciers that are relevant to the emerging topics of climate change and conflict. It noted that climate change impacts on the mountain water cycle (reflecting changes in snow cover and glaciers) lead to increased water stress or conflict, especially in areas where dry seasons are evident. It reported that these conflicts can be found on a local and regional scale, as well as on a national and transboundary scale. It noted the socio-political conditions that contributed to this tension; in addition to the pronounced dry season, these included power inequalities among water users and weak regulatory systems, especially in transboundary situations. It reports cases of these patterns in several glacial regions, including Central Asia, South Asia and the Andes; This view is consistent with discussions in Chapter 7 of the report and elsewhere on climate change as a “threat multiplier” that exacerbates pre-existing social and political tensions.

However, the report also points out steps to resolve these conflicts. Chapter seventeen, Decision options for managing risk, discusses Argentina’s Glacier Protection Act, which promotes actions to minimize the intrusion of mining and other businesses into glacial areas, and protect water supplies, at least in the short and medium term.This discussion of glacier change and conflict is broader than the brief mention in the 2019 Special Report on the Ocean and Cryosphere — a sign that the international community is waking up to the nature of climate change as one of the factors causing political tension.

Grinnell Glacier, on Baffin Island in the Canadian Arctic, is now smaller than at any time in the past 40,000 years. CEDIT: Gregory Smith/flick

Adaptation and Indigenous Knowledge

Chapter Twelve, Central and South Americanoting that since the 1980s, glaciers in the Andes have lost one-third to one-half—where there are large indigenous peoples—and correlate this change with impacts on ecosystems, water resources, livelihoods and natural disasters such as floods and landslides) impacts.

Chapter Sixteen, Key risks across industries and regions Noting that shrinking glaciers are putting communities in many areas at risk of water shortages. In South America and elsewhere, they face some limitations in improving water management as an adaptive strategy, as governance systems are often characterized by distrust, rigidity and unequal power relations. While these constraints were described as “soft” or ones that could be overcome, the report pointed to other “hard” or fixed constraints, such as the loss of livelihoods and cultural values ​​due to the biophysical processes of glacier shrinkage. This chapter also describes mountain glaciers as a unique and threatened system whose limited geographic extent and other unique properties lead them to be classified as a “cause of concern”.

However, the report also discusses some effective responses to these impacts.

chapter 2, Terrestrial and freshwater ecosystems and their services, contains extensive case studies of the impacts of climate change on the socio-ecological systems of the Andean region. Faced with the loss of pastures due to retreating glaciers and reduced meltwater, the Quechua and Aymara indigenous pastoralists increased their mobility, using social and economic connections to access new pastures, building canals to irrigate new pastures, and turning to growing fodder. This case shows the importance of addressing glacier retreat by incorporating indigenous knowledge into planning – which is linked to the strong presence of indigenous and local knowledge throughout the report. However, the diversion of water from the mountains to large capitalized agribusinesses in far-flung coastal regions has further depleted water resources, while some poorly regulated mining companies in the region have polluted streams, increasing pressure on these communities and reducing water resources. their ability to adapt.

A herdsman and her daughters from Chilca, Peru, with their cattle. resource: Alison Kane

The importance of good governance

In conclusion, this report shows the importance of glaciers in many regions, where they form part of ecological, economic and social systems. It traces new discoveries in the natural sciences that have emerged over the past few years. It documents, more clearly than previous reports, the importance of policy and governance, key elements of addressing the impact.

The resourcefulness of the indigenous peoples of the Andes mentioned in the previous section is a good example. These communities are acutely aware of changes in the glaciers and have found ways to adapt to them — even though they are challenged by disproportionate influences that rob them of the powerful benefits of water resources. This power imbalance within South America and other power imbalances between countries and interest groups seeking to drastically reduce emissions parallel those who prefer to maintain emissions.

In the report, Glacier illustrates the key theme of the report: the stark difference between a world with lower emissions and more effective policies and a world with higher emissions and mismanagement.

Ben Orlove is an anthropologist at the Columbia Climate Institute, founder and manager of Glacierhub, and lead author of Working Group II of the IPCC Sixth Assessment Report.