3 Degrees More

With current policies the Earth is on track to a warming of around 3 °C above preindustrial temperatures, a level of heat our planet has not seen for millions of years. Ecosystems, human society and infrastructure are not adapted to these temperatures. Due to non-linear effects, the impacts will be much more severe than just three times as bad as after 1 °C of warming. Land areas will continue to warm much more than the global average, many regions twice as much or even more. Extreme heat will become far more frequent and a major cause of human mortality, making large parts of the tropical land area essentially too hot to live. In addition, extreme rainfall and flooding, droughts, wildfires and harvest failures will increase in frequency and severity. The destructive power of tropical cyclones will also increase. Sea-level rise will accelerate further, and the destabilization of ice sheets will commit our descendants to loss of coastal cities and island nations. The risk of crossing devastating and irreversible tipping points of climate and biosphere will rise to a high level. This 3-degree world is not an inevitable fate, but action to prevent it must be swift and decisive.

Rising temperatures worldwide are already causing significant shifts in the distribution ranges of plant and animal species (range-shifts). Paleontology also knows this phenomenon from earlier phases of global warming. Migration and dispersal of warmth-loving species that have been carried away by the movement of human goods will give rise to communities of organisms of hitherto unknown composition (novel communities), about whose stability little is known today. At the same time, the temporal sequences are also shifting. The formerly synchronized occurrence of plant and animal species increasingly no longer matches (mismatch). The effects of climate change first show up in individuals, depending on their genetic characteristics, and then propagate, bottom-up, through populations to ecosystems in which many individuals of different species interact with each other. During extreme climatic events such as marine or terrestrial heat waves, mass mortality events can occur, as recently in the Pacific Northwest. Climate change is not the cause of the biodiversity crisis we are currently experiencing but threatens to dramatically exacerbate it in future.

Against the background of a brief history of global agricultural production of the last 12.000 years with a focus on the last 100 years, illustrates the challenges today’s food system is confronted with given an unfortunate but likely scenario of a +3° temperature increase. Our review of the available evidence paints a quite dreadful picture. A moderate gain in the area suitable for agriculture is confronted with substantial yield losses through strains on crop physiology, multitrophic interactions, and more frequent extreme events. Self-amplifying feedbacks are unresolved and might lead to further unexpected losses. Consequently, all well-known pathways to eradicating global hunger while bending the curve of biodiversity loss need to be implemented today: Transitioning to less energy-rich diets, closing yield gaps through agroecological principles, adopting modern breeding technologies to foster stress resilience and yields, minimizing harvest losses and food waste and a trade system that serves to distribute food fairly and to compensate for possible climate-related yield losses, while locally adapted cultivation methods should be developed further and not be replaced. Efficiency gains in agriculture only, albeit indispensable, will not be enough to achieve food security under severe climate change.

There is growing awareness that the extreme impacts of climate change drives people to migrate, domestically, regionally and internationally. The growing body of available research evidences that climate change reshapes when, how and where people migrate across the world. As a results, states are increasingly considering policy changes to address the urgent challenges of now and of the future. His paper provides a brief overview of some key issues relevant to climate migration and discusses some of the policy options for shaping future action.

The early 2020s have illuminated how rising temperatures and intensified weather extremes can affect many different areas of life, thus costing us a lot—immaterial costs and actual money. This is just a preview of a world in which global mean temperature could be 3 degrees higher than in pre-industrial times and in which weather extremes would be even more frequent and intense. But what is the total economic impact of climate change? How can it be separated from that of other crises and events? What are plausible effects in different sectors, how do they interact and how do they affect macroeconomic growth in the short- and long-run? In this chapter, we shed light on these questions. Based on the current state of science, we present and discuss various transmission channels from the physical impacts of climate change to the economy, including potential interaction effects, and outline possible consequences and risks for the economy as a whole. A guiding question for these discussions is how future damages can credibly be estimated.

Considered as a state, forests are the third-largest emitter of carbon after China and the United States. 80% of biodiversity depends on protecting the forests. Some two-thirds of wildlife populations have already disappeared.

Wood use and forest loss constitute immense climate problems! Forests are urgently needed as a carbon sink. The one-sided narrative of carbon storage in wood products and of the uses of wood as a substitute material thus detracts from sound and necessary action for climate and biodiversity protection.

The “regenerative” sustainable energy source forest is too small. The current use intensity is aggravating our acute climate crisis.

Clear-cutting and clear-cutting-like interventions are endangering the climate and biodiversity. Allowing trees to age, preserving deadwood, and allowing natural regeneration with adapted game populations would have a positive effect on climate and biodiversity, and help mitigate forest damage.

We need ambitious action to achieve compliance with the Paris Climate Agreement. Forests should be part of the solution that would reduce our current emission by around 15%.

Climate and biodiversity protection must become central political goals and instruments—cross-sectoral and authoritative at all political levels. There must be no climate protection at the expense of biodiversity protection.

There are only two ways to slow down the increase of the carbon dioxide content of the atmosphere effectively: On the one hand, CO₂ emissions from fossil sources and from land use changes can be reduced, and on the other hand, terrestrial CO₂ reservoirs can be increased, mainly by increasing forest cover. The latter, forest increase is particularly effective in terms of carbon ecology if it takes place in the tropics and subtropics, where the growth and thus also the CO₂ reduction potential is particularly high. Afforestation- provided it is carried out with site-appropriate adapted tree species- has a number of other positive effects, such as the prevention of erosion and flooding or the creation of work and recreational opportunities.

In an ever warming world the need for action on the mitigation of climate change and climate restoration is overdue. To stay within the Paris Agreement guardrail of 2 °C above pre-industrial level of atmospheric CO₂, the global economy and transport system must be decarbonized by 2050 at the latest. With the climate system more and more out of balance the need for additional carbon removal from the atmosphere will be inevitable. But how can this be done? One scalable solution is a transition of the building sector towards a sustainable bio-based construction economy. Based on the transdisciplinary idea of the Bauhaus movement in the early 20ies of the last century, the Bauhaus Earth was founded to bring their vision and ideals to live today with the climate crisis at its core. Key are climate-friendly materials, integrated planning and nature-based design. Sustainable forestry provides an extraordinary building material, which combined with today’s technology and innovation will transform cities into wooden human-made carbon sinks in order to restore the global climate, tenth by tenth of a degree Celsius.

Peatlands contain more carbon than the entire global forest biomass, but their importance has long been overlooked. Currently drained peatlands (on 0.4% of the world’s land area) cause greenhouse gas emissions that amount to almost 5% of the worldwide total. Most of these emissions come from lands used for drainage-based agriculture and forestry. To meet the climate goals of the Paris Agreement, all intact peatlands must remain wet and all already drained peatlands (500,000 km²) must be rewetted. Any peatland use should only take place under wet conditions.

The greatest challenge for rewetting lies with peatlands in intensive agricultural use. These lands urgently need alternative (wet) production methods (paludiculture) to allow productive use while avoiding the environmental harm from conventional drainage-based peatland use. This requires cross-sectoral national peatland protection strategies with measures to strengthen structures and promote innovation. The massive implementation on the ground, however, is best left to the self-directed momentum of enterprises and markets steered by climate protection rewards (“carbon credits”) as a transitional strategy to facilitate a rapid start-up of peatland rewetting. In this way, companies can compete with drainage-based peatland use until paludiculture is technically fully mature and economically self-sustaining.

Agricultural practices can contribute to climate change mitigation by storing—“sequestering”—carbon in soil and plants, while at the same time increasing soil fertility and water storage capacity, improving yields and nutrient supply, creating drought-tolerant soils, regenerating degraded cropland and rangelands, and enhancing biodiversity—all with positive impact on the local economy. Together, these form a set of compelling solutions.

The continued destruction of forests, the deterioration of soils, the subsequent loss of terrestrial soil water storage and the reduction of water retention in the landscape are disrupting the movement of water in and through the atmosphere. This disruption causes major shifts in precipitation that could lead to less rainfall and more droughts in many areas of the world, increases in regional temperatures and an exacerbation of climate change. These changes affect regional climate, but can also impact regions far away. Understanding the interwoven relationships and the subsequent fluxes of energy between plants, soils and water on the ground, as well as in the atmosphere, can help mitigate climate change and create more resilient ecosystems.

Climate change introduces significant sociopolitical challenges, potentially deepening societal divisions or promoting social cohesion. Lower-income households, the less educated, and parts of the lower middle class bear the brunt of rising costs resulting from climate policies. In contrast, wealthier households, despite contributing more to CO2 emissions, experience fewer financial implications and have a better capacity to adapt. The new German government takes steps to compensate lower-income households through measures like covering the EEG levy with taxes and additional climate payments, yet the effectiveness of these actions remains in question. Achieving climate goals requires rigorous control of complex processes related to dismantling, renovation, and construction. Collaboration between the state and private enterprises is emphasized to establish a socially ecological market economy. Adapting individual behavior for climate protection poses challenges, as restrictive policies have been met with resistance. Many parties now prioritize technological advancements and positive incentives to encourage climate-friendly practices. In conclusion, climate policy has the potential to either deepen societal divisions or strengthen social cohesion. This underscores the importance of broad inclusivity, new participation models, and reforms within existing forums.

This chapter deals with solutions, affordability and the power of civil society to keep climate change within tolerable limits.

Due to the Intergovernmental Panel on Climate Change (IPCC), the consequences of a global warming of +1.5 °C have been and are mainly explained and communicated. However, we are heading for +3 °C by the end of the century. Due to the non-linear progression of the consequences of increasing global warming, this leads to a world that becomes a threat to all of humanity and to all societies. The overwhelming majority of the world’s population is unaware of this.

In order to prevent such a devastating “three-degree scenario”, democracies need three prerequisites: Information campaigns by politicians make the population aware of the consequences of +3 °C global warming and assure that no further financial burdens will fall on the majority of the population (climate justice). In addition, the Paris climate treaty must be supplemented: Nature-based solutions must immediately become part of climate protection policy; they can be implemented promptly, at relatively low cost and, above all, in a socially acceptable manner. The political will to invest at least about two trillion US$ annually (2% of the world social product) in climate protection policy by the year 2050 must be organized. Two types of tax, the inheritance tax and the financial transaction tax, are the focus for raising the financial resources for this investment requirement.