An urgent call for action to restrict climate change and reverse biodiversity loss

from Academic Societies

Today an increasing number of organisations are challenging political leaders to strengthen their climate-related policies: climate marches, days of action, strikes of school children and university students, demonstrations and petitions, and legal actions against inactive governments. The recent global assessment on biodiversity and ecosystem services by IPBES clearly demonstrates the dramatic loss of biodiversity in recent decades. Climate change and biodiversity loss are now recognized as major threats to the Earth’s biosphere and the safety and wellbeing of future generations.

In the face of the overwhelming evidence documenting climatic change and the erosion of the Earth’s living fabric, we, as a scientific community have the responsibility to support the current cry for action. We emphasize that the scientific findings gathered by the extensive work of many researchers, from a wide range of disciplines and synthetized by major global scientific organizations (IPCC, IPBES…) need to be used to inform direct and unprecedented politicy actions. Only by acting quickly will we be able to stabilize climatic conditions and protect vital biodiversity and ecosystem function.

From recent IPBES and IPCC reports (referenced below), we know that:

  • The surface temperature of the Earth is increasing. The mean temperature is now 1°C higher overall compared to the period of 1850 – 1900.
  • Warming is almost exclusively the result of human activities, through combustion of fossil fuels, destruction of natural ecosystems, intensive agriculture practices, amount of livestock, and soil degradation.
  • The temperature increase has already amplified the frequency and intensity of extreme climatic events such as heat waves, droughts and floods. The more the Earth warms, the more often such events will occur. A temperature increase above 2°C will trigger an additional amplification of this trend, making it critical to limit temperature increases to below 1.5°C.
  • Global warming directly affects human health. It will make extensive areas inhospitable to human life and will increase population displacements.
  • It will require huge efforts to adapt agricultural and industrial practices.
  • Climate change has direct negative effects on biodiversity and on the services it provides to human societies.
  • Human activities also directly impact biodiversity and ecosystem functions, exacerbating the negative effects of climate change. Habitat loss from land-use change, our modes of consumption and of food production, overuse of resources from the oceans, have weakened the ability of ecosystems to mitigate the impacts of climate change.

To limit the increase in temperature to 1.5°C, the world’s CO2emissions need to decrease by 45% in 2030 compared to 2010 and become neutral by 2050.

However, COemissions continue to increase year after year and currently proposed actions will not keep global warming below 3°C by the end of this century, and a 5°C increase is most likely. The consequences of warming Earth’s ecosystems to this extent, and its subsequent impacts on biodiversity, human societies and economy, will be enormous, increasing tensions for resource acquisition. These consequences will be irreversible for centuries. There will be no remediation options if we fail to act now from local to global scales. The current trajectory will cause perturbations of a magnitude that largely exceeds anything that human societies have ever experienced.

Beyond individual actions, it is crucial that far reaching, structural actions are immediately taken. They require radical changes in our current modes of production and consumption at local and global scales. The transition towards reduced energy use and renewable energy sources has to intensify immediately. We have to shift now to modes of production and consumption that do not impact biodiversity, alongside a major effort to restore a biosphere better able to cope with the challenges posed by a changing climate. The longer we delay action the more difficult and costly the task will be. We reaffirm that there is no alternative.

The knowledge and means towards a society achieving zero emissions and respect of biodiversity already exist. Current global subsidies supporting the fossil energy industries currently exceed 500 billion dollars per year. Even a partial reassignment of this budget would facilitate the transition towards a more sustainable and sober society. Ensuring this transition urgently means a shift to renewable energy sources, to buildings producing energy rather than consuming it, fundamental changes in mobility and transportation. It also means the cessation of habitat loss through urban sprawl and agricultural development, a more sustainable agriculture producing less CO2 and more favourable to biodiversity, and habitat restoration that includes ecologically sound reforestation in place of deforestation.

Limiting global warming and loss of biodiversity needs the joint collaboration and participation of all stakeholders: individuals, the private sector, and governmentsFor this, we have to take into account the diversity of human situations, life styles and possibilities, in order to improve social equitability. This is an indispensable requirement to ensure adhesion by all to the collective effort.

Governments must show political courage and act now. However, changes are unlikely without civic pressure and without intense, thoughtful and continuous mobilisation. As scientists, we join current movements and the call to political and economic leaders for action. Effective and equitable measures can still ensure a viable future for humans and all other living organisms – provided these measures are taken immediately.

A few recommended resources

IPBES, 2018: Assessment reports, on pollinators, pollinations and food production, on land degradation and restoration, on biodiversity and ecosystem services for Europe and Central Asia, for Asia and the Pacific, for Africa, for the Americas, and on Scenarios and Models of Biodiversity and Ecosystem Services. Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany.

IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups  I,  II  and  III  to  the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.

IPCC, 2018: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. IPCC, Geneva, Switzerland.


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