According to a recent study prepared by the University of Hawaii and published in Nature scientific journal on October 10th, unprecedented global changes are about to happen. Scientists predict the year at which the Earth’s climate will shift beyond the past 150 years’ variability as early as 2047 under the business-as-usual scenario and 2069 if greenhouse gas emissions (GHG) are stabilized. The “Projected Timing of Climate Departure from recent Variability” study adds new information supporting the global importance of switching to fossil-fuel free energy as soon as possible.
Historic variability and predictions for the next 100 years
Scientists have estimated the pace of climate change by calculating an index based on the minimum-maximum range of mean annual temperatures of 1860 – 2005 (the “historic variability”). The data comes from 39 Earth System Models developed independently by 21 climate centers in 12 different countries. ”The models have been effective at reproducing current climate conditions and varied in their projected departure times by no more than five years, which proves the study’s validity.
Starting from this historic variability, the scientists projected the temperatures of the next century, to discover the year when the mean annual temperature will exceed historic boundaries, defined as the year of the climate departure. The calculation method works for “any given location”, and projections were created covering the world’s major cities.
Mean annual earth’s near-surface air temperature calculations were essential, but the study also integrated additional climate variables such as precipitation and evaporation. The ocean’s surface temperature and pH were also taken into account to determine the biodiversity implications of climate change.
“Business-as-usual” versus stabilized GHG scenarios
There are two major scenarios of climate’s evolution depending on the future concentration of GHG in the atmosphere. If the concentration continues to grow, reaching 936 CO2 parts-per-million (ppm) by 2100 – the “business-as-usual” scenario RPC 85- the climate departure year will occur sooner. If the atmosphere’s CO2 concentration stabilizes at 538 ppm (RPC 45, or “optimistic” scenario), the process will be obviously delayed. However, calculations show that the difference between the two climate departure times is usually not longer than two decades.
Main results: tropics will be affected first, within a decade
Depending on exact location on the earth, climate departure timing varies, but the overall figures are alarming. With the global average year of climate departure predicted just 34 years from now, major changes will occur much sooner for countries such as Indonesia – the city of Manokwari’s projected year is 2020 under stabilized GHG scenario and 2025 for the worst case scenario. India’s average projected year is 2045 / 2069 (optimistic / business-as-usual scenario), with major cities such as Mumbai having an earlier timing (2034 / 2051). Countries located along the tropics will be affected first: Nigerian city of Lagos will experience unprecedented climate warming in 2029 / 2043; Colombia’s capital Bogota’s projected years are 2033 / 2047;for Mexico City, the projected figures are 2031 / 2050.
The explanation why these countries are affected sooner relies in the existing geographic and climatic features of the tropics. This area has almost constant, hot and humid conditions that have registered little variation along the centuries. Therefore, their narrow climate boundaries can easily be exceeded by the fast changes in the earth’s atmosphere. To make matters worse, “small but fast changes in the climate could induce considerable biological responses in the tropics, because species there are probably adapted to narrow climate bounds”. This phenomenon will affect the area’s biodiversity in an unprecedented ay, with most species forced to rapidly adapt to the new changes either migrating to cooler areas or going extinct.
Implications of the study’s predictions and other views
This new research predicts that climate change will determine severe “ecological and societal disruptions”, due to the complexity of the worldwide symbiosis between natural resources and man-made systems. “The impacts on the tropics have implications globally as they are home to most of the world’s population, contribute significantly to total food supplies, and house much of the world’s biodiversity”. Food crisis is one of the most direct implications, but thinking at the whole food supply chain – from the fuel needed to transport the food to the supermarket to the energy it needed to process and preserve it under steady-state conditions in our refrigerators- prices will probably go up dramatically. This overarching phenomenon is already happening, and nowadays everybody seems to try to cope with the ever-increasing cost of daily life. Financial sites such as money.co.uk offer advice on reducing energy bills, by shopping for energy-efficient electrical appliances, for instance, as this is a common problem. Although the correlation between global warming and costs increasing may be criticized by skeptics, the Nature study is not the only warning issued recently. The Intergovernmental Panel on Climate Change (IPCC) just published its Fifth Report in September 2013, warning that following a predicted 5 – 9 centigrade increase in global mean temperatures, food crisis is imminent. The report also states a 95% certainty that global warming is the product of anthropogenic-sourced GHG emissions.
USA’s projected climate departure timing
According to the University of Hawaii’s study, the USA’s average climate departure year is 2051 / 2078 (stabilized atmosphere/ business-as-usual scenarios), with Honolulu having the earliest timing (2043 / 2047) and Anchorage the latest (2071/2095). Depending on their location, major US cities will be affected by the unprecedented shift beyond recent climate variability as early as 2043 / 2073 (Phoenix, Arizona) or 2046 / 2075 (San Diego).For Washington DC and New York, the projected year of climate departure has been calculated as 2047 / 2071, while cities like Austin and Dallas will experience the phenomenon later (2058 / 2090 and 2063 / 2093). Across the nation, major changes will occur affecting life at all levels.
The need to develop alternative energy solutions across the world is becoming crucial in the light of this new research. This unprecedented climate shift will affect our lifestyle severely in a few decades, and the phenomenon will continue, affecting the future. As shown by the study, in order to delay the global implications of this phenomenon started in the industrial era, it is critical that we reduce greenhouse gas emissions as soon as possible.
Autthor: Melissa Whitehall