climate change smoke stacks Lukas Schulze/Getty Images

Is Hothouse Earth Avoidable?

If our planet becomes just 2°C warmer than pre-industrial temperatures, we may find ourselves irreversibly headed toward a scenario characterized by excruciatingly high temperatures and frequent extreme weather events. Only rapid economic transformation can reduce the risk of such an outcome.

STOCKHOLM – Nearly 50 years ago, the Club of Rome’s report “Limits to Growth” warned that if economic growth continued apace without regard for the environment, the world could face ecological and economic collapse in the twenty-first century. Yet that is essentially what has happened. As new research for the Club of Rome shows – and the latest report from the United Nations Intergovernmental Panel on Climate Change (IPCC) reiterates – the world may well be headed toward disaster.

Many wrongly interpreted the “Limits to Growth” as an attack on unbridled economic expansion. In fact, the report argued that if the unlimited-growth pathway was chosen, it would require complementary policies (including funding) to preserve the planet’s finite life-support systems.

This argument has been ignored. Instead, the world has continued to pursue unbridled growth, without regard for the environmental consequences. This has enabled us to make enormous strides in reducing poverty, increasing longevity, and increasing wealth. But it has come at a high cost to the fabric of society and the resilience of the planet.

As scientists have conclusively shown, in the last decade, we have entered a new geological epoch, the Anthropocene, in which human activity – in particular, economic activity – has been the dominant factor influencing Earth’s climate and environment. In the Anthropocene, our planet’s life-support system is changing faster than ever.

Climate change now represents a clear and present danger. If our planet becomes just 2°C warmer than pre-industrial temperatures, we may be placed irreversibly on the path toward “Hothouse Earth” – a scenario in which temperatures are many degrees warmer than today, sea levels are considerably higher, and extreme weather events are more common – and more devastating – than ever.

This need not be the case. For its 50th anniversary, the Club of Rome updated the “Limits to Growth” report’s “World 3” computer model. Using economic and social data from the last five decades, the so-called Earth 3 simulation provides new projections about the future impact of human activity.

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We based our analysis on the UN Sustainable Development Goals, agreed upon by world leaders in 2015. The 17 SDGs include social objectives like ending poverty and improving health, as well as critical environmental targets, including halting species extinctions, protecting our oceans, and reducing greenhouse-gas emissions. To determine whether the world may be able to meet these goals by the 2030 deadline, we considered four scenarios, ranging from business as usual to total economic transformation.

The business-as-usual scenario, our analysis shows, would not bring significant progress toward achieving the SDGs or boosting environmental sustainability by 2030. Perhaps unsurprisingly, the scenario characterized by faster economic growth would also pose a serious threat to environmental sustainability.

But even a third scenario, which includes stronger policies to protect the environment, would put the planet’s stability at risk. In any of these scenarios, human wellbeing could improve in the short term, but would be severely undermined in the longer term, as we blew past planetary boundaries and tipping points.

There is just one scenario that can deliver improvements to human wellbeing in an environmentally sustainable way: the path of “transformational change,” brought about by a shift to unconventional policies and measures. In our analysis, we identify five areas where such change is particularly important.

  • In line with the IPCC’s recent report, exponential growth in renewable energy is needed to enable the world to halve total emissions every decade from 2020.
  • Sustainable food production must be boosted substantially. Feeding almost ten billion people by 2050 will require a radical overhaul of existing food systems, with an additional 1% in sustainable intensification each year.
  • Developing countries need new development models, following examples like China, Costa Rica, Ethiopia, and South Korea, with a strong emphasis on sustainability.
  • The world must drastically reduce inequality, ensuring that the richest 10% capture no more than 40% of total income.
  • Finally, we must stabilize the global population by making huge investments in universal education, gender equality, health care, and family planning.

We do not claim to have provided a definitive list of transformative reforms the world needs. Our key message is that the only way to balance growth and sustainability is through structural and societal transformation on a global scale.

The good news is that we believe that the transformational scenario presented here is possible. There are already signs that market forces can spur a new energy revolution – one that would be both technically feasible and economically attractive. Technologies to support sustainable agriculture already exist, with around 29% of all farms already using some form of sustainable farming techniques. And, globally, we have reached “peak child,” and the number of children is no longer growing.

But there remain high political barriers to renewable energy and, even more so, to reducing inequality. Making matters worse, in the three years since world leaders agreed to the SDGs, there has been a growing backlash against multilateralism. At precisely the moment when global cooperation is most needed, many countries are embracing nationalism, isolationism, and trade protectionism.

Most rational analysts would argue that keeping the planet healthy enough to support a thriving economy in the long term is a good investment. But, as we are seeing today, such long-term thinking does not always lend itself to political success. To protect our planet – and, in turn, our civilization – voices like that of the Club of Rome are more important than ever.