I was in Jeddah, Saudi Arabia, on a day in July 1995 when the noontime temperature rose to almost 50 degrees Celsius. Saudi Arabia had its record hottest temperature on June 22, 2010 at 52.0°C (125.6°F) in Jeddah. The record heat was accompanied by a sandstorm, which resulted in 8 electric power plants to fail.
Extremes of weather that persist over long periods are not new and what seems like small changes in average weather temperatures can have catastrophic impacts in some parts of the world — for example before this century ends, areas from North Africa, the Middle East, South Asia (North India, Pakistan and Bangladesh) and China, may become uninhabitable in summer months.
Jeddah on the Red Sea is the gateway to Islam's holiest cities — Makkah, in the south, and Medinah in the north — and it's not inconceivable from 2070 onward that the annual Hajj pilgrimage will coincide with a heat wave in Saudi's commercial capital that will make the city uninhabitable.
The five hottest years on record across the globe were in 2016, 2015, 2017, 2018, and 2014. Nine of the 10 warmest winters have happened since 2005 and in the United States, 2018 was the 14th warmest of the 124 years on record, at least for the contiguous 48 lower states. .
2018 was so hot that global land and ocean-surface temperatures were 0.79°C (1.42°F) above the 20th-century average, the US National Oceanic and Atmospheric Administration (NOAA) reported. Since 1880, when record-keeping began, only three years — 2016 (the highest, in part because of the El Niño weather pattern that begins off the northwest coast of South America), 2015 and 2017 — were hotter.
The area most impacted by climate change is the Arctic, which is warming between two and three times faster than the global average according to NOAA.
Carbon impact
According to NASA (the US National Aeronautics and Space Administration), ancient air bubbles trapped in ice enable scientists to step back in time and see what Earth's atmosphere, and climate, were like in the distant past. "They tell us that levels of carbon dioxide (CO2) in the atmosphere are higher than they have been at any time in the past 400,000 years. During ice ages, CO2 levels were around 200 parts per million (ppm), and during the warmer interglacial periods, they hovered around 280 ppm (see fluctuations in the graph below). In 2013, CO2 levels surpassed 400 ppm for the first time in recorded history. This recent relentless rise in CO2 shows a remarkably constant relationship with fossil-fuel burning, and can be well accounted for based on the simple premise that about 60% of fossil-fuel (for example oil and coal) emissions stay in the air."
Donald Trump, a president of the United States, who has called himself "a very stable genius, has in the past termed climate change "a Chinese hoax." Last January Trump used the incidence of a polar vortex to justify his climate change scepticism. The genius who has threatened legal action if his education records are released, thinks weather variations debunk the scientific evidence of climate change.
In the beautiful Midwest, windchill temperatures are reaching minus 60 degrees, the coldest ever recorded. In coming days, expected to get even colder. People can’t last outside even for minutes. What the hell is going on with Global Waming? Please come back fast, we need you!
— Donald J. Trump (@realDonaldTrump) January 29, 2019
Scientists prefer to use “climate change” rather than "global warming" when describing the complex shifts now affecting our planet’s weather and climate systems.
Is the Sun causing global warming?
According to NASA, the above graph compares global surface temperature changes (red line) and the Sun's energy received by the Earth (yellow line) in watts (units of energy) per square metre since 1880. The lighter/thinner lines show the yearly levels while the heavier/thicker lines show the 11-year average trends. Eleven-year averages are used to reduce the year-to-year natural noise in the data, making the underlying trends more obvious.
The US agency adds that the amount of solar energy received by the Earth has followed the Sun’s natural 11-year cycle of small ups and downs with no net increase since the 1950s. Over the same period, global temperature has risen markedly. It is therefore extremely unlikely that the Sun has caused the observed global temperature warming trend over the past half-century.
"We know subtle changes in the Earth’s orbit around the Sun are responsible for the comings and goings of the ice ages. But the warming we’ve seen over the last few decades is too rapid to be linked to changes in Earth’s orbit, and too large to be caused by solar activity.
One of the 'smoking guns' that tells us the Sun is not causing global warming comes from looking at the amount of the Sun’s energy that hits the top of the atmosphere. Since 1978, scientists have been tracking this using sensors on satellites and what they tell us is that there has been no upward trend in the amount of the Sun’s energy reaching Earth.
A second smoking gun is that if the Sun were responsible for global warming, we would expect to see warming throughout all layers of the atmosphere, from the surface all the way up to the upper atmosphere (stratosphere). But what we actually see is warming at the surface and cooling in the stratosphere. This is consistent with the warming being caused by a build-up of heat-trapping gases near the surface of the Earth, and not by the Sun getting 'hotter.'"
Greenhouse effect
Bob Ward of the Grantham Research Institute on Climate Change and the Environment, London School of Economics, wrote in the Financial Times:
"Our knowledge of the causes and potential consequences of climate change is based on multiple lines of scientific evidence, collected over about 200 years. For instance, John Tyndall (an Irish-born physicist) performed laboratory experiments in the mid-19th century showing that carbon dioxide is a greenhouse gas, helping to keep the earth’s surface about 33°C warmer than it otherwise be. Svante Arrhenius a Swedish scientist) published calculations in the 1890s of the likely warming that would result from the carbon dioxide that would be released by burning all of the known reserves of coal.
Current levels of carbon dioxide are more than 45% higher than they were before industrialisation. The geological evidence indicates that the last time such concentrations existed was about 3m years ago when global temperatures were more than 3°C warmer than today, the polar ice caps were much smaller and worldwide sea levels were up to 20m higher."
NASA says scientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect" — warming that results when the atmosphere traps heat radiating from Earth toward space.
"Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and do not respond physically or chemically to changes in temperature are described as 'forcing' climate change. Gases, such as water vapour, which respond physically or chemically to changes in temperature are seen as 'feedbacks.'"
Rising sea levels
The US Global Change Research Program (USGCRP) is a Federal program mandated by Congress and it says:
"Global average sea level has risen by about 7–8 inches (about 16–21 cm) since 1900, with about 3 of those inches (about 7 cm) occurring since 1993. Human-caused climate change has made a substantial contribution to sea level rise since 1900, contributing to a rate of rise greater than during any preceding century in at least 2,800 years.
In addition to the global average sea level rise, local sea level rise – sometimes called 'relative sea level rise' – happens at different rates in different places. Local sea level rise is affected by the global sea level rise, but also by local land motions, and the effects of tides, currents, and winds. Many places along the United States coast have seen their local sea levels rise faster than the average global rate. As sea levels have risen, the number of tidal floods each year that cause minor impacts, often called 'nuisance floods,' have increased 5- to 10-fold since the 1960s in several US coastal cities (very high confidence). Rates of increase are accelerating in over 25 Atlantic and Gulf Coast cities (very high confidence).
A new NASA study shows that warming of the tropical oceans due to climate change could result in a substantial rise in the frequency of extreme rainstorms by the end of the century.
National Geographic:Is global warming real?
Scientific consensus
Multiple studies published in peer-reviewed scientific journals show that 97% or more of actively publishing climate scientists agree, according to NASA that, "Climate-warming trends over the past century are extremely likely due to human activities. In addition, most of the leading scientific organisations worldwide have issued public statements endorsing this position."
The UN Intergovernmental Panel on Climate Change (IPCC), which was established in 1988 to provide policymakers with regular scientific assessments on the current state of knowledge about climate change, in October 2018 said in a report that global warming could still be held to 1.5°C, or 2.7°F, of warming relative to preindustrial levels, especially if net human-caused carbon dioxide emissions decline by 45% by 2030 compared to 2010 levels, and reach "net zero" by roughly mid-century.
The IPCC says, "Climate-related risks to health, livelihoods, food security, water supply, human security, and economic growth are projected to increase with global warming of 1.5°C and increase further with 2°C."
"12 years isn't a deadline, and climate change isn't a cliff we fall off — it's a slope we slide down," said Kate Marvel, a climate scientist at NASA. "We don't have 12 years to prevent climate change — we have no time. It's already here. And even under a business-as-usual scenario, the world isn't going to end in exactly twelve years."
"All the time-limited frames are bullshit," Gavin Schmidt, of NASA's Goddard Institute for Space Studies in New York, told Axios, an online news service, in an email. "Nothing special happens when the 'carbon budget' runs out or we pass whatever temperature target you care about, instead the costs of emissions steadily rise," he said. The IPCC report, for example, found the impacts worsen considerably beyond 1.5°C of warming.
"The thing to push back against is the implicit framing that there is some magic global mean temperature or total emissions that separate 'fine' from 'catastrophic'. There just isn't," Schmidt said.
Wet-bulb temperature and human survival
Scientists at the Massachusetts Institute of Technology (MIT) using high-resolution versions of standard climate models say a tipping point for human survival involves a measurement called the “wet-bulb temperature” that combines temperature and humidity, reflecting conditions the human body could maintain without artificial cooling. That threshold for survival is no more than 6 unprotected hours at 35°C or about 95°F, according to recently published research.
The scientists say that the Persian/Arabian Gulf and Red Sea region in Southwest Asia, has shallow water and intense sun, that make it “a specific regional hotspot where climate change, in absence of significant mitigation, is likely to severely impact human habitability in the future.”
The researchers say that while the Gulf region has a relatively small, relatively wealthy population and little agricultural land, the areas likely to be hardest hit in South Asia, specifically northern India, Bangladesh, and southern Pakistan are home to 1.5bn people. These areas are also among the poorest in the region, with much of the population dependent on subsistence farming that requires long hours of hard labor out in the open and unprotected from the sun.
The last region the MIT researchers looked at was the North China Plain (NCP) in the heartland of modern China.
Elfatih Eltahir at MIT and Suchul Kang at the Singapore-MIT Alliance for Research and Technology said in their research paper last year that while the earlier studies found serious looming risks, the new findings show that the NCP faces the greatest risks to human life from rising temperatures, of any location on Earth.
The three regions the researchers studied were picked because past records indicate that combined temperature and humidity levels reached greater extremes there than on any other land masses. The study shows that there has been a substantial increase in extreme heat waves in the NCP already in the last 50 years.
One of the surprising findings was the significant contribution by irrigation to the problem — on average, adding about a half-degree Celsius to the overall warming in the region that would occur otherwise.
Many of the NCP region’s 400m people are farmers and have little alternative to working outside.
Reducing carbon emissions in China and India will continue to be a challenge given the low ownership of vehicles compared with advanced countries.
European emissions and Ireland's poor record
Eurostat reported last March that the European Union (EU) had close to 182m hectares of forests and another wooded land in 2015, corresponding to 43% of its land area. Wooded land covers a slightly greater proportion of the land than the area used for agriculture (some 41%).
In 7 member countries, more than half of the land area was wooded in 2015. Just over three-quarters of the land area was wooded in Finland and Sweden, while Slovenia reported 63%. The remaining four EU states, each with shares in the range of 54–56 %, were Estonia, Latvia, Spain and Portugal.
Sweden reported the largest wooded area in 2015 (30.5m hectares), followed by Spain (27.6m hectares) and Finland (23.0m hectares). Of the total area of the EU covered by wooded land in 2015, Sweden and Finland together accounted for 29.4%.
Eurostat said last year that the EU as a whole was on track to reduce greenhouse gas emissions by 20% in 2020 compared with 1990 levels (including international aviation and indirect CO2 emissions).
In 2016 Austria, Cyprus, Ireland, Portugal and Spain were the only EU countries that had increased emissions from the base year of 1990. See Eurostat reports here and here.
In 2016 Ireland's emission rate was 46% above the EU28 average.
Eurostat: Greenhouse gas emissions per capita 2017
The first chart below was produced by the Irish Environmental Agency (EPA) in 2016 and it is in respect of emissions outside of the EU's Emissions Trading Scheme (ETS).
The Irish Department of Communications, Climate Action & Environment says:
"The 2009 Emissions Trading Directive established a cap and trade system for GHG emissions associated with large industry and electricity generation installations across the EU. The EU ETS includes some 11,000 installations (101 currently in operation in Ireland of which 75 are industrial installations), with an installed capacity of more than 30MW. It covers about 45% of EU emissions, but only just over 25% of total emissions in Ireland."
The second chart was produced by the EPA in respect of total emissions in 2009.
Research by the Sustainable Energy Authority of Ireland (SEAI) published in 2018 showed that Irish households emit almost 60% more CO2 than the average EU home.
The Climate Change Performance Index 2019, a ranking of a country’s aggregated performance regarding 14 indicators within the four categories “GHG Emissions,” “Renewable Energy” and “Energy Use,” has Ireland at the 48th rank of 56 countries in the world. The United States was second last, ahead of Saudi Arabia.
Ireland has the worst record of the EU28!
Even the extension of forestry to counter carbon emissions is claimed to be a potential disaster for birds, according to an Irish writer in The Guardian last year.
Sir David Attenborough (1926-), English broadcaster/natural historian
