Sometimes, a few indicators can tell a whole story. The year 2014, for example, will mark the highest level of global greenhouse gas emissions ever – with no end of this unwelcome growth trend in sight. At the same time, 2014 was the hottest year since large-scale measurements began some 135 years ago.

It is scientifically well-established that these two trends are interlinked as rising global emissions will keep pushing the climate system to extremes never witnessed before in the course of human civilization.

While the present gives reasons for concern, the future under business-as-usual could be outright disastrous: under current emission trends, the world is on a course for a 4°C rise up until the end of the century, far beyond the politically agreed objective of limiting the global average temperature increase to no more than 2°C compared to pre-industrial times.

The dire consequences of a 4°C world have been shown in three reports published by the World Bank and led by the Potsdam Institute for Climate Impact Research. The “Turn Down the Heat” series takes a risk perspective to provide robust information for policy-makers, business executives, and indeed all citizens who take responsibility in the world we live in and we will leave to future generations.

The twin challenge

In particular, the nexus between climate protection and development is a striking conclusion of the World Bank analysis: without climate stabilization at still manageable levels, development advances, especially in the poorest countries, are set to be reversed. Indeed, development work of past decades (involving significant financial resources) is at risk and with it the well-being of the most vulnerable citizens on Earth.

While no nation will be immune to the impacts of climate change, the studies show that the distribution of impacts is likely to be unequal, impacting particularly many of the world’s poorest regions, which have the least capacity to cope and to adapt. Approaching and crossing tipping points in the climate system would also have destabilizing effects on societies and indeed undermine human security. In this respect, even purely regional perturbations in poor nations could have severe global repercussions.

As much as climate impacts have to be looked at on a regional and even local scale in order to devise appropriate adaptation strategies, climate protection is a global endeavor with success or failure mirrored by the level of global greenhouse gas emissions and their future evolution. Here, the test will be the commitment to real action by all emitters individually and collectively so as to bring about the global emissions peak as soon as possible – preferably before the end of this decade to keep the 2°C guardrail well in sight.

The much publicized twin announcement of post-2020 actions on climate change by the US and China last November is a telling example of the current political dynamic. Compared to unbridled emissions growth, the plans are undoubtedly an important step in the right direction. But they are still far from being sufficient in both a national and global perspective: currently accounting for over 40% of the global share, the absolute level of emissions of the two countries combined will keep rising and per capita emissions are set to converge in the range of 12 tons by the end of next decade – more than twice the current, unsustainable, global average. Yet the later we act, and hence the more emissions accumulate, the more costly it gets both in terms of climate damages and mitigation costs.

Crunch time for our climate

2015 will be a decisive year in this regard as the outcome of the Paris Protocol will impact the living conditions on the planet for generations to come. Enshrining the 2°C guardrail in international law and elevating it to a joint commitment by the international community would be a critical step forward.

A dual approach is needed to close the ambition-action gap. To start with, we need to see the creation of a virtuous circle of nation states and committed partners. All countries will have to take action in order to avoid the further build-up of fossil fuel-based infrastructures with emission lock-ins lasting for decades.

Broad-based carbon pricing would be an essential element for containing emissions across countries, and ultimately at the global scale. Second, since all emitters need to take action, substantial assistance in terms of financing and technology for mitigation and adaptation in countries with fewer resources will be required.

It is here where the common but differentiated responsibilities, as called for by the UN Framework Convention on Climate Change, chiefly come into play. Realizing their pledge and equipping the Green Climate Fund with annual resources to the tune of $100 billion is a major responsibility for the developed world.

In the end, combating climate change requires global cooperation on an unprecedented scale. It is the biggest challenge for humanity to date but – if addressed in time – it can equally become its finest hour.

Author: Dr. Daniel Klingenfeld, Head of Director’s Staff, Potsdam Institute for Climate Impact Research

Image: A villager walks in front of a coal-fired power plant on the outskirts of Datong, Shanxi province, November 20, 2009. REUTERS/Jason Lee