28 April – Sandra van der Hel

The ‘tipping point’ metaphor in science and the news media

In December 2005, the NASA climate scientist James Hansen stated in his address to the American geophysical Union (AGU) that “we are on the precipice of climate system tipping points beyond which there is no redemption”. With this statement he warned the public for the dangers of abrupt and irreversible climate change. Since Hansen’s speech, the tipping point metaphor has become part of the common lexicon of climate scientists and journalists.

In this talk, we discuss the bridge building role of the tipping point metaphor between science and the news media, and we describe how the use and meaning of the tipping point metaphor developed in interaction between the these two domains. Within the scientific domain, the metaphor developed from a rhetorical device to convey a message of dangerous and abrupt climate change, to a theory constitutive scientific concept. This is reflected in the domain of the news media, which increasingly takes on the metaphor as given when talking about changes in the climate system. Moreover, both domains developed a creative use of the tipping point metaphor, drawing on the metaphor both to point out the dangers of abrupt climate change, and to call for societal change to avoid a climate change catastrophe.

We conclude by pointing to the ambiguity embedded in this metaphor, which allows it to be used for various purposes, in different contexts, and with different meanings attached.