Limiting the effects of climate change will be necessary to achieve sustainable development, equity and poverty eradication. It raises challenging issues of equity, justice and fairness as all countries, irrespective of where they are on the development spectrum, will share the consequences of not taking mitigating and adaptive actions. Furthermore, many of those most vulnerable to climate change are developing countries that have contributed least to greenhouse gas (GHG) emissions.
By not tackling climate change now, the burden shifts to future generations, increases the risks of severe, pervasive and irreversible impacts for people and planet, and undermines the basis for sustainable development.
Climate change is the greatest market failure the world has ever seen.Stern (2007)13.1
Goal 7 of the Millennium Development Goals sets out to ensure environmental sustainability. Specifically, the plan targeted the reduction in consumption of ozone-depleting chlorofluorocarbons are generally consider to be non-toxic, non-flammable chemicals containing atoms of carbon, chlorine, and fluorine.
more and the emissions of carbon dioxide (CO2) per capita. Considerable success was achieved in eliminating ozone-depleting substances and the ozone layer is expected to recover during the next 40 or 50 years. There has been considerably less success in reducing global CO2 emissions, which actually increased by 50 per cent between 1990 and 2012 (United Nations Framework Convention on Climate Change (UNFCCC), 2015).
Sustainable Development Goal 13 continues the agenda set out in Millennium Development Goal 7 and calls for a renewed and strengthened effort to address climate change, in particular through the integration of climate change mitigation and adaptive measures into national strategies and the implementation of existing commitments13.2. The scientific data relating to this field is complex and highly specialized13.3, but one of the key objectives of the UNFCCC 21st annual session of the Conference of the Parties (COP 21) (Paris) agreement is to limit the rise in global temperatures to within 2°C of pre-industrial levels. Scientists project that a doubling of pre-industrial CO2 levels will likely cause global average surface temperature to rise between 1.5°C and 4.5°C compared to pre-industrial temperatures. Pre-industrial levels of CO2 are generally thought to be around 280 parts per million (ppm), although this estimate is contested (Ball, 2008). In 2013, CO2 levels exceeded 400 ppm for the first time in recorded history (United States National Aeronautics and Space Administration (NASA), 2013). Its concentration in the atmosphere is now higher than at any time in the last 800,000 years (BBC, 2015). Figure 13.1 shows how average global land-ocean temperatures have been rising, more or less steadily, since the early 1900s, but that there has been a noticeable acceleration in the trend since the 1970s.
Anthropogenic or human-induced GHG emissions13.4 have increased since the pre-industrial era, driven largely by economic and population growth, and are now higher than ever. This has led to atmospheric concentrations of not just carbon dioxide, but also methane and nitrous oxide that are unprecedented in at least the last 800,000 years. Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-twentieth century. Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850. The period from 1983 to 2012 was likely the warmest 30-year period of the last 1,400 years in the northern hemisphere. Surface temperature is projected to rise over the 21st century under all assessed emission scenarios. It is very likely that heat waves will occur more often and last longer, and that extreme precipitation events will become more intense and frequent in many regions. The ocean will continue to warm and acidify, and global mean sea level to rise (IPCC, 2015).
Climate change will amplify existing risks and create new ones for natural and human systems. Those risks are unevenly distributed and are generally greater for disadvantaged people and developing countries. IPCC predicts a greater likelihood in climate-related extremes such as heat waves, droughts, floods, cyclones and wildfires (IPCC, 2015). Figure 13.2 shows that the number of catastrophic loss events13.5 have more than doubled over the past 35 years, rising from 133 in 1980 to 359 in 2015. Geophysical eventsEarthquakes, tsunamis, volcanic activity.
more have been reasonably stable, but there has been a noticeable increase in meteorological eventsTropical, extratropical, convective and local storms.
more, rising from 45 in 1980 to 123 in 2015. The same is true for hydrological eventsFloods and mass movements of water.
more, rising from 43 in 1980 to 171 in 2015 and climatological events Extreme temperatures, droughts, forest fires.
more (from 18 in 1980 to 37 in 2015).
According to another data source that has broader coverage of sources13.6, the number almost trebled over the past 35 years, and the total catastrophic loss events was rising from 360 in 1980 to almost 1.000 in 2015. Since 1980, there have been 21,700 loss events, claiming almost 1.7 million lives and costing in the region of US$4.2 trillion in damages (Munich RE, 2015). In 2015 alone, these events caused 23,000 fatalities and US$100 billion worth of damages (Munich RE, 2016). Comparing 2015 with 1980, the proportionate growth in hydrological eventsFloods and mass movements of water.
more and climatological events Extreme temperatures, droughts, forest fires.
more is evident – in 1980 these events combined accounted for roughly 35 per cent of all loss events and in 2015 they accounted for 50 per cent. (Munich RE, 2015, 2016).
The evidence of human influence on the climate system is clear and mounting. IPCC warns that if mitigating and adaptive action is not taken, the risks of severe, pervasive and irreversible impacts for people and ecosystems (including hazardous events) will magnify, as will risks of long-lasting changes to the global climate system. The exact levels of change that could activate or trigger abrupt and irreversible effects remain uncertain, but the risk associated with crossing such thresholds increases with rising temperature.
Climate change is predicted to have a detrimental impact on food security. In particular, it will most likely have a negative impact on global marine species and biodiversityVariability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.
more in the next 40 to 50 years. As marine organisms face progressively lower oxygen levels, higher rates and magnitudes of ocean acidification and rising ocean temperatures, coral reefs and polar ecosystems will degenerate and many marine species will face extinction, undermining sustainable fishing. On land, production yields of wheat, rice and maize in tropical and temperate regions will be negatively impacted as temperatures increase. While many terrestrial, freshwater and marine species will continue to change their geographic ranges, seasonal activities and migration patterns, most plant species cannot naturally shift their geographical ranges sufficiently fast to keep up with projected rates of climate change, thus leading to loss of species on a large scale.
Climate change is also projected to reduce renewable surface water and groundwater resources in most dry subtropical regions, intensifying competition for water. Melting snow and ice are altering hydrological systems and raising sea levels, which pose negative risks for land available for both agriculture and human habitation.
Stabilizing temperature increase to below 2°C relative to pre-industrial levels requires urgent and fundamental changes from
business as usual. Moreover, the longer action is delayed, the greater the costs and technological, economic, social and institutional challenges facing people and planet. Continued emission of GHGs will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.