Emissions pendulum

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Energy-related carbon dioxide emissions: North America (million tonnes carbon) To a large extent, policies to reduce emissions in Policy First and Sustainability First can harvest co-benefits with other policy imperatives. Source: IMAGE 2.2 (see technical annex)

As a predominant emitter of greenhouse gases, North America plays a major role in determining the future climate of the planet. In Markets First the region's refusal to participate notably hampers international efforts to control emissions of these gases. The region remains the highest emitter on a per person basis and also among the highest in absolute terms (see chart). This happens despite overall improvements in energy efficiency stimulated by increasing fuel prices and general technological advance. Transportation-related emissions show the sharpest increase as motor fuel gains a greater share of total energy consumption, pushing up total emissions as it does so. The collapse of parts of the transport infrastructure and the growing restriction of ownership of fossil-fuel-powered vehicles to the elite in Security First are not enough to counteract the overall impacts of expanding population, resulting in even greater increases in emissions in this scenario.

In a world of Policy First, North America's success in implementing policies to reduce carbon emissions in an economically efficient manner leads to reductions in the region's contribution to global emissions. Nevertheless, emissions per person remain relatively high, at over twice the world average. Emissions from transport and other sources decline through a combination of increased fuel efficiency and greater use of public transport. Even more spectacular results are seen in a world of Sustainability First as greenhouse gas emissions plummet, a goal thought to be unrealistic just a few decades earlier. This transformation is due to technological advances, but more importantly to changes in lifestyle reflected in reductions in per person energy use to the point where it is only slightly higher than that in other developed countries.

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Extent of built-up areas: North America (% of total land area) Source: PoleStar (see technical annex)

One of the most visible impacts of reliance on the automobile is urban sprawl - low urban population densities with heavy reliance on personal transport. The dominance of the automobile culture is also a major factor in local air pollution. These issues continue to plague many cities in the region in both Markets First and Security First. In the Markets First scenario, the built-up area expands over time (see chart), continuing an upward trend in the region, albeit more slowly than in the past. Combined with rising population, the built environment per person expands significantly.

In Security First, faster population increase and sprawling settlements lead to even greater growth in built-up areas. Here, the sprawling urban spaces that are the legacy of the 20th century are further burdened with a decaying infrastructure. Waste treatment declines steeply and water-borne diseases spread. Populations also rise in the Policy First scenario, but a tendency towards more compact settlements stabilizes the built-up area. In Sustainability First, the values of the scenario are reflected in much more compact settlements than in the past, or in the other scenarios. Combined with relatively smaller populations, the builtup area declines as the scenario unfolds.

A Policy First world sees the built-up environment creating less pressure on land resources and ecosystems (see chart below). More effort is put into repairing ageing infrastructure, particularly in the inner cities. In Canada, large land areas continue to be set aside for indigenous people, with likely positive future outlook for many of the ecosystems involved. However, very extensive mining, hydropower, oil and gas development projects, along with forest road construction continue to reduce wilderness areas. In Security First and Markets First, exploration processes increase substantially, not least in Alaska, Yukon and Quebec, although these inroads are slightly smaller in the former scenario due to lower economic growth.

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Land area impacted by infrastructure expansion: North America (% of total land area) Source: GLOBIO (see technical annex)

Going further in a world of Sustainability First, the great urban centres of North America begin a slow process of reorganization in response to the popular desire for greater proximity of home, work, commerce and leisure activity. For many, the 'towns within cities' that begin to emerge from the process by 2032 provide an attractive balance between access to a lively culture and the immediacy of a small community. Others opt for greater access to green spaces, leading to small towns dispersed around larger metropolitan centres, connected by advanced transport systems.

Continued advances in information technology expand the options for living and working arrangements and a diverse range of lifestyle choices emerges. A common feature of most of these lifestyles is that they are far less resource intensive, automobile-dependent and stressful than their 20th century antecedents. People enjoy a strong sense of affiliation with their local, national and global communities.

Climatic change and the introduction of exotic species pose additional threats to land-based biodiversity in the region. Although natural forest area remains relatively constant in the region in all scenarios, in some cases there is swift expansion of plantations, built areas and agricultural land, with associated infrastructure. This is particularly the case under the Markets First scenario with its strong economic growth. The diverse biota found in wetlands also continues to be threatened by conversion and degradation of these ecosystems.

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Natural Capital Index: North America An index of 100 is the situation when total land area is undomesticated and all pressures are below the minimum threshold (see technical annex). Reduction in the Natural Capital Index indicates habitat loss and increasing pressure on terrestrial and aquatic biodiversity. Source: IMAGE 2.2 (see technical annex)

Natural vegetation in much of the region, particularly in the north, is threatened by changes in climate. There are slightly greater impacts of climate change in Policy First and Sustainability First scenarios, reflecting the short-term effects of efforts to reduce other pollutants, especially sulphur dioxide, in addition to greenhouse gases. However, over the next 30 years the climate change situation is dominated by the momentum built up before 2002 and there is little overall difference in Natural Capital Index between the scenarios (see chart). The full effects of climate change will be apparent only after 2032.

Biodiversity in coastal and marine ecosystems also faces threats from infrastructure development, pollution and climate change. In the cases of Sustainability First and Policy First, the slower growth in infrastructure and significant changes in agricultural policy lead to important reductions in land-based sources of pollution. The effects of climatic changes lag somewhat behind those on landbased biodiversity, because of the slower changes in water temperature, but significant threshold effects may play a role here. In fisheries, greater cooperation both within the region and with other regions in Policy First and Sustainability First contributes to the preservation and restoration of important fish stocks. Some of the pressure on marine resources is reduced by the expansion of aquaculture in these scenarios, as well as in Markets First. The potential for international conflicts over marine resources within the region and with other regions is high in Security First, with negative implications for the health of aquatic ecosystems.