Ecosystem Alterations: Frequently Asked Questions

Below are some questions that are frequently asked in relation to the text "Ecosystem Alterations". This page presents a shortened version; the complete and updated text is available in the Kindle version.

Is it true that we have only a few years left before the end? Are we at risk of extinction?

Humans have always prophesied their own end, it is likely a cultural fact independent of objective metrics. Historically, where man ventured out of his comfort zones, he tended to expect the worst, imagining his end or that of the whole world. Not surprisingly, old geographic maps often represent, along the borders, a fairly clear indication: hic sunt leones or also hic sunt dracones.

To say that we are on the brink of extinction is a reckless and unfounded statement, especially in light of the macro-trends (population growth and life expectancy for example). As some researchers claim, the opposite may also be true, that is, man is able to harness his adaptive capacities and technologies to avoid an event that would normally have led to the extinction of the species (see for example Juan Enriquez, https://www.ted.com/talks/juan_enriquez_we_can_reprogram_life_how_to_do_it_wisely and Lauren Sallan, https://www.ted.com/talks/lauren_sallan_how_to_win_at_evolution_and_survive_a_mass_extinction).

Are newspapers a good source of scientific information?

Generally no. There can be well-documented and comprehensive insights, but the information conveyed by newspapers is typically partial and structured to create so-called clickbait headlines. This translates into a presentation of content geared towards strong and atypical arguments, while overlooking aspects that may be central in the original research. Often the studies cited are not even contextualized, so it is not possible to know if they are prepared by independent institutes or if they are researches that have at least in part originated from contexts that can condition the results themselves (private groups, NGOs, academic institutions, public bodies, etc.).

Should we act immediately?

Yes and no. The principle of urgency should be applied where it is necessary. To say that we must act immediately or that environmental or climate policy is on the brink, promotes a view that carries risks. On the one hand, it tends to conceal the evident steps forward and the concrete results achieved in the last 40 years. Above all, it prevents effective planning of the next interventions. If everything is governed by the principle of urgency, the risk is indeed not to identify those sectors where urgency is real and important.

Should we change the world?

As in the previous question, we must be aware that environmental policy, in recent decades, has achieved positive results. The critical issues are evidently not lacking, but a radical change is not a particularly effective or indicated solution, also due to the possible social impacts that this could entail. Rather than changing, we need to improve and optimize the management of natural resources.

Are the data generally reliable?

Much of the research conducted on the topics covered in this text relies on quantitative methods, measured using usually declared and replicable methods. It is clear that there are studies that can be influenced by external factors or by the bias of the researchers themselves. It can be useful to check who the promoters of the investigations are (academic institute, NGO, government, etc.) and what methodological choices they have adopted. Often statistical analysis techniques come into play that can indeed be used to argue in favor of a thesis (see next question).

Are environmental disasters increasing?

Often in the media, you find numbers and charts attesting to a sharp increase in natural disasters or insurance expenses related to climate events. These are data to be taken with some caution, as growth is not necessarily linked to an increase in the frequency or intensity of natural events. These data indeed conceal other factors (dark data) such as the strong demographic growth of the last century, the drastic increase in built-up surfaces (urbanization) and their respective water refluxes, as well as the overall strong increase in the insured value at the level of built heritage.

Other variables indeed provide opposite indications, such as the average number of deaths caused by natural disasters, which has sharply decreased over the last century (a significant figure in light of demographic growth). Here too, however, it is difficult to establish direct correlations: it is indeed a positive result to which numerous factors have contributed (prevention and intervention systems, consolidation of structures, etc.).

Is human health in danger? Are cancer cases increasing because of our actions?

Based on trends recorded by major indicators, human health is not in danger, on the contrary, the average life expectancy has only lengthened.

As in the case of endangered species, the number of tumors also confronts us with a problem related to the reference population. Demographic growth and access to care by an ever larger slice of the human population have certainly caused a significant increase in registered cases. It should also be considered that technological development has made it possible to better identify different cancer cases.

In addition to demographic growth, with the lengthening of life expectancy, there are more opportunities to develop a cancer case during life.

Like other topics, fear is often used to catalyze change. Is it a good solution?

Fear is a strategy that works very well in the short term, but it risks being counterproductive on other time scales. Linking environmental policies to the "global warming" theme can be risky: as has happened in the past, changes can occur unexpectedly in the complex systems that regulate Earth's autopoiesis. And if the climate started to show contrasting signs, what consequences would there be on policies and public opinion, accustomed to a narrative built on certain predictions? In the long term, it is better to work by focusing on a serious and factually sustainable management of resources, so as to consequently influence the alterations of the systems.

Do climate changes really exist?

Among the few certainties that we can identify, one is this: climate changes do exist, and anyone who denies this is on the same level as flat earthers. Changes in climate systems have always existed, slow or rapid, due to internal as well as external factors. The problem that arises today is to know if and to what extent the ongoing climate changes are influenced by human activities.

Is change synonymous with deterioration?

Clearly, the dominant communication highlights the potential catastrophic impacts of change: this is a dynamic common to other sectors and in some ways hostage to the "good news = no news" model. The reality is less schematic: changes indeed occur with uneven intensity and frequency. This means that in some areas of the world changes will be imperceptible, in others they will have positive impacts and in others still negative.

Can we talk about a Climate Hell or Environmental Cataclysm?

It's difficult to justify the adoption of extreme visions, at least within the context of research texts or with scientific aspirations. It's better to confine such descriptions to post-apocalyptic movies and books.

Are the data on global warming reliable?

The scientific community seems to be largely in agreement: we are facing global warming. However, it should be noted that the climate is a complex system, with resilience and autopoiesis. From this perspective, the data collected today can be used to optimize sectoral public policies. On the other hand, the interpolation towards the future remains problematic, as already seen in many predictions promoted in the past. Finally, there is less certainty about the degree of responsibility of human activities on this trend: from those who consider it limited, to those who consider it total.

Are glaciers disappearing?

Yes, glaciers are disappearing: this is an incontrovertible scientific observation. The few exceptions do not seem to be significant compared to the global trend. Even in this case, the data must be contextualized: choosing different time scales, this decline assumes different values. In past epochs, glaciers could be completely absent or cover large surfaces of the emerged lands: this means that there is no ideal equilibrium condition. The underlying issue concerns the role of man in the last recorded drop: none, limited, or absolute? It's a question to which it is difficult to give a univocal answer.

Are glaciers disappearing because of humans?

The last glacial period, the Würm glaciation, ended roughly between 16,000 and 14,000 BC and began about 115,000 years ago. During this glaciation, vast stretches of Canada, Northern Europe, and Russia were covered by immense ice caps. Due to the formation of these ice caps, a large amount of water was taken from the oceans. This phenomenon led to a significant reduction in sea level, about 120 meters compared to current levels. At the same time, the climate was generally colder and drier than today. It is estimated that average temperatures were 5-10°C lower in areas directly covered by glaciers and 4-5°C lower in tropical regions. These climatic conditions brought about profound transformations in flora and fauna. Many animals, like mammoths, cave lions, and woolly rhinos, thrived in this cold climate, while forests were largely replaced by grasslands and tundra in many regions.

On the European continent, during the peak of the last glaciation, a vast portion of the northern territories was covered by glaciers. Countries such as Great Britain, Ireland, Scandinavia, and parts of Germany, Poland, and Russia were submerged under thick ice caps. This glacial advance left an indelible mark on the European landscape: vast valleys, lakes, and other geographical features, especially in the Alpine and Scandinavian regions, are the direct result of the erosive action of glaciers. The epilogue of this glaciation marked the beginning of an interglacial period, the Holocene, during which we witnessed a milder and more stable climate, creating the ideal conditions for the development of human civilizations as we know them today.

Given this context, it's challenging to support theories that attribute glacier melting to human actions. It's a trend that has continued for tens of thousands of years; the growth of human activities has likely contributed to accelerating and reinforcing these processes.

Is sustainable development synonymous with ecological development?

In many studies, the imperative of sustainability is focused on the ecological component. In the perception of some authors, economy and society are marginal vertices. It should be emphasized that sustainable development aspires to build a human community that lives and works with dignity. In summary, therefore, they are not synonymous: sustainable also means ecological, but not only. Therefore, they are not synonyms.

What relevance should be given to the choice to limit the use of straws?

The plastic straw, after several decades of pervasive use, has undergone a significant reduction in recent years within the broader context of the fight against plastics. Leaving aside the economic and social issues of this rapid change, one might question how actually relevant this product is from an environmental impact perspective. Reading articles appearing in the media, we learn that we are dealing with a huge quantity of straws: 1.6 straws per person per day in the USA, a similar value for Europe. These are estimates that probably overestimate consumption, but they allow us to roughly quantify production. We know that a straw weighs on average 0.4 grams and - wanting to exaggerate - we can estimate a global annual production of 1'153'000 tons of plastic (population 7.9 billion, 1 straw per person per day). In the context of global plastic production, we are talking about 0.25%: in fact, 460'000'000 tons are produced each year (data referring to 2020, OECD Global Plastics Outlook Database). Considering these figures, replacing straws (or not using them at all) is a useful but little relevant gesture. However, it should be borne in mind that - although limited in quantitative value - the phenomenon can become more significant considering its easy dispersion in the environment (like bags and bottles).

Should we give up flying to save the planet? Do airplanes pollute more than other means of transport?

Some issues, like the pollution caused by aviation, are particularly favored by the media and by some schools of thought, a legacy of an era when airplane contrails were blamed for causing global cooling. Today, it is possible to estimate with relative (not absolute!) precision the ecological footprint of different modes of transport: however, it should be noted that this is a complex analysis that can determine very different results, depending on the parameters used (number of passengers per vehicle, type of vehicle, reference year, etc.). For example, extreme results can be obtained by referencing a large-engine car from the 1980s and assuming one or two passengers per trip. Conversely, the energy efficiency of a private electric vehicle, occupied by 4 people, can be better than that of a train with an average occupancy rate. To return to air transport, it is worth emphasizing that it is a sector that overall is responsible for 2% of the global volume of emissions and 12% of those generated by the transport sector.

Source: Smil, Vaclav. I numeri non mentono: brevi storie per capire il mondo. Torino: Einaudi, 2021.

In some publications, reference is made to the fact that airplane emissions, occurring at high altitudes, are more harmful to the environment. This phenomenon is particularly associated with gases responsible for the "greenhouse effect" global warming. In reality, the causal link is not easy to demonstrate: it seems rather a legacy of the theories related to the ozone hole, where it was believed that emissions at high altitude were more harmful than those emitted at low altitude.

Analyzing the ecological footprint is difficult, especially in light of rapid technological changes and different energy structures between countries: the impact in terms of emissions of means powered by electricity is very different if a nation produces it with coal (India) or with nuclear power (France). Undoubtedly, the narrative promoted by large environmental NGOs based on outdated information and articulated for not always transparent purposes is not constructive.

At the same time, other issues that determine significant impacts but are in fact unpopular and counterproductive in fundraising are not taken into account. A phenomenon that has grown significantly in recent decades, little studied, concerns, for example, the ecological footprint of domestic animals. Or that of mobile phones: 1.75 billion of these objects were sold in 2020. Vaclav Smil, in the book entitled "Numbers Don't Lie", poses this problem in a chapter with an explanatory title: "Does your car or your phone do more harm to the environment?"

Should we be ashamed to fly?

As seen earlier, based on the data on impacts, we should not be ashamed to fly. In general, it is better to be wary of those who want to blame or introduce a danger system that judges the behaviors of others. In this case, not only is the aviation sector at risk (responsible, it should be remembered, for 2% of total greenhouse gas emissions), but a large part of the activities that define us as a human community.

More roads equal More traffic?

In certain areas of thought, it happens with some frequency to hear that the more infrastructure is built (roads, railway lines, etc.) the more traffic they generate. From a purely statistical point of view, it is difficult to support this principle of causality: as in other areas, it seems more appropriate to call into question the socio-demographic factors that are at the root of the problem. It should also be noted that the reference population has increased significantly: this factor alone should make us reflect on the possible repercussions of a block at the level of support infrastructures, whether related to traffic or other distribution networks (water, sewerage, electricity). In summary, therefore, the demographic increase and the increase in the frequency of private and professional movements represent the variables that largely determine the impact on transport infrastructure and traffic.

Is it true that due to humans more and more species are going extinct?

(source: IUNC, 2021)

Based on the work carried out by the IUCN, we can say that the number of species at risk or endangered is increasing, but it is necessary to keep in mind that the reference population is also increasing. In percentage terms, these two variables allow for a decreasing percentage. In other words, the fact that the increase in censused species is more marked than that of endangered species is positive. Considering the still uncertain context, with 93% of species not evaluated, it is still advisable to cautiously evaluate these dynamics, whether they are catastrophic or optimistic.

What are mass extinctions?

In narratives promoted by some organizations, mass extinctions are those caused by human activities. In reality, these specifically refer to five major extinctions that have been recorded in the history of our planet. Over the ages, there have been periods when the extinction rate has been particularly high (at least 75% of species extinct in less than two million years). In the last 500 million years, 5 particularly intense events have occurred:

1. The Ordovician–Silurian extinction event: 443 million years ago
2. The Late Devonian extinction: 359 million years ago
3. The Permian–Triassic extinction event: 252 million years ago
4. The Triassic–Jurassic extinction event: 201 million years ago
5. The Cretaceous–Paleogene extinction event: 66 million years ago

These events have led to the disappearance of between 75% and 96% of all species on Earth. They were caused by massive volcanic eruptions, asteroid impacts, and rapid climate changes. In these contexts, the concept of a sixth extinction caused by human activity appears to be more of a narrative tool than a scientific fact.

Do ecosystems develop linearly?

No, the evolution of an ecosystem is better represented by systemic, complex, autopoietic development. In models, this aspect tends to be simplified, favoring linear developments and the blocking of variables. Another aspect, which plays an underestimated role over longer time scales, concerns randomness. A volcanic eruption, an earthquake, a solar disturbance or another major natural event, can determine changes such as to overturn the previous functioning models.

Which sectors are those that have the greatest impacts on ecosystems?

In general, it is difficult to give an exclusive answer, given the heterogeneity of ecosystems. However, it can reasonably be stated that the sector that shows the most significant impacts is that of energy production (electricity, heating, transport): it accounts for 73.2% of total greenhouse gas emissions. On this front, public policies are intervening by supporting renewable energies, in particular solar and wind, as well as the development of new technologies.

Are there sustainable cities?

Is deforestation still ongoing?

Yes, deforestation is still ongoing, albeit at a lower intensity compared to the past. The rate of deforestation reached its peak during the 1980s, a decade that resulted in the loss of 150 million hectares of forest (like the Amazon rainforest).

Since then, numerous factors have contributed to a rather marked reversal, dropping to 78 million hectares in the 1990s, 52 in the first decade of 2000, and 47 between 2010 and 2020. Temperate forests have for some decades recorded a positive reforestation rate, amounting to 6 million hectares in the last decade: this trend, called the forest transition point, allows us to be optimistic about the future of rainforests.

Roland Hochstrasser, geographer

New impulses, suggestions, and additions are always welcome