There are many signs that the climate is already changing. Yet some think that climate change is only going to happen by the end of the century. Because of this common misunderstanding, the urgency of climate change has been misunderstood by most.
The end of the century is the timeframe often used by climate scientists to project changes in the average weather (temperature, precipitation and wind conditions) over a long period of time (usually, 30 years). Using climate models, scientists also analyze how the climate is projected to change decade by decade throughout this century.
Climate change is happening now, and much faster than anticipated. The evidence is what most have been experiencing as unusual weather events, such as changes in average rain patterns leading to floods or droughts, more intense storms, heat waves and wildfires, among others daily examples46. Some of these impacts of climate change already had devastating effects on livelihoods, infrastructure and lives.
There is public agreement that a 2ºC increase in global warming should be avoided. In fact, the Paris Agreement set a global average temperature target of well below 2ºC above pre-industrial levels. Some policymakers and civil society groups advocated for a higher ambition target, and a 1.5ºC above pre-industrial levels target was also included. The IPCC has been requested to produce a special report on the impacts, feasibility and costs of the 1.5ºC target.
However, the 1.5ºC target has almost certainly already been missed because of the lack of action to stop the increase in global GHG emissions for the last 20 years. Global average temperature has already reached 1ºC above pre-industrial times in 2015, as reported by the World Meteorological Organization47. This is a significant increase, compared to the 0.85ºC above pre-industrial times in 2012 reported by the IPCC48. An additional warming of 0.4-0.5ºC is expected as a consequence of GHGs that have already been emitted. This additional increase in global temperature is due to the slow response of the ocean-atmosphere system to the increased atmospheric concentrations of GHGs49.
Global GHG emissions are not projected to decrease fast enough, even if all the pledges are fully implemented. Full implementation of the pledges will require the promised US$100 billion per year in financial assistance for developing countries to be realized. As a result, the 1.5ºC target could be reached by the early 2030s and the 2ºC target by 205050.
The main concern is not when the 2ºC target will be exceeded, but the impacts of climate change resulting from such an increase in global temperature. Weather-related events due to climate change have doubled in number since 199051. An increase in global average temperature of 2ºC within the next couple of decades implies an additional doubling in the number of these events.
As the number of weather-related events due to climate change continues to rise, their impact on water resources, food production, human health, services and infrastructure in urban and rural areas, among other sectors52, will be more frequent and intense. Some of the impacts of climate change may be beneficial, while most will not, negatively impacting lives and livelihoods everywhere.
There is still time to slow down the current path towards reaching the 2ºC target within the next few decades. There are two positive aspects towards changing this trend. First, and most importantly, there are still four years before the implementation of the INDCs in 2020. By 2018, all countries agreed to revise their pledges –sufficient time to significantly raise the ambition of actions to reduce GHG emissions and to adopt the necessary policies for their effective implementation in all countries. Second, the IPCC has already committed to improving its communications to make their reports more accessible for the public to understand.
46. IPCC, AR5, WG II, Summary for Policymakers (2014) ↩
47. Status of Global Climate in 2015, World Meteorological Organization (2015) ↩
48. IPCC, AR5, WG I, Chapter 2 (2013) ↩
49. IPCC, AR5, WG I, Chapter 12 (2013) ↩
50. IPCC, AR5, WG I, Annex II, Table AII-7-5 (2013) ↩
51. Loss events worldwide 1980 – 2014, Munich RE (2015) ↩
52. IPCC, AR5, WG II, Technical Summary (2014) ↩