The framework of ‘Romanization’ developed by Haverfield in 1905 - that Romans ‘civilized’ their imperial subjects, particularly those in ‘barbarian’ western provinces - remains hegemonic, notwithstanding multiple revisionist attempts. It has been reasserted, rejected, or modified, but still frames the debate. Yet, the postcolonial project to decolonize the production of historical knowledge has prompted some scholars to seek fresh approaches and to rewrite the history of Roman imperialism. This book asks: what is the value of postcolonialism in the discourse on Romanization? How has it influenced the discourse on Romanization thus far? Can postcolonialism move the discourse on Romanization forward? Borrowing Said’s concept of travelling ideas, this book undertakes a comparative study between the point of departure and the point(s) of arrival of travelling ideas of postcolonialism to understand their path and impact in the discourse on Roman imperialism and Romanization.

We experience weather in the air around us, and that implies climate: the statistics of weather. But if we are to understand climate, and especially how it changes, we need to examine all its interactions with the planet. In the previous chapter we looked at the role of sea-surface temperature. If we are to go further, we need to look at other components of our planet and their atmospheric interactions. When we see the range of interconnections, we realise that we are dealing with a complex system, with multiple interactions between components. Whenever we see such a system, we must realise the potential for one interaction between components to end up impacting back on another: this is feedback. If we are to understand climate, we must understand these feedbacks. In the last sections we will illustrate one of the most important of these processes with a ‘relatively simple’ model.

A fundamental tenet during the forest-climate debate was that evapotranspiration cools the surface climate and provides water vapor that condenses and falls back onto the land in a recycling of precipitation. It is this process by which tropical forests lessen the heat and promote rainfall through a positive feedback between forest cover and rain. The premise, too, of irreversible climate change, voiced in the decline of ancient civilizations due to deforestation, was common. In today’s climate science, the Amazonian rainforest is a case study for forest-climate coupling, and one in which deforestation is a possible tipping point that irreversibly changes the climate. Many participants in the debate speculated that planting trees in the Sahara would increase rainfall. A green Sahara has, in fact, occurred in the past and increased rainfall at the time. This, too, provides another climate tipping point. The boreal forest presents a further example of positive feedback by which the northward advancement of the treeline in a warmer climate decreases albedo and reinforces the warming; the southward retreat of the treeline with a cooler climate conversely exacerbates the cooling.

This chapter offers the story of the green movement since the 1950s as a case study in how to bring about deep and lasting societal change in the absence of full political consensus. Over the past 60 years, green activists have not succeeded in fully realizing their goal of a sustainable economic system, but they have succeeded in bringing pervasive changes to modern economic, social, and energy systems. By pursuing an eclectic, decentralized, and multifaceted set of strategies over many decades, they have made a significant positive impact. A similar strategy is likely to work best for building new systems of global governance for mega-dangerous technologies. Climate change may prove to be a uniquely potent unifying factor for humankind over the coming decades, allowing effective mobilization for incremental reforms. The reasons for this are threefold: climate change is not subject to the logic of arms races; it threatens to bring tangible harms that affect all human beings; and its disasters will escalate gradually over the coming decades, giving people a chance to wake up and respond constructively.