Last year was Kenya’s coolest of the past four, with temperatures averaging 21.82 degrees Celsius as per the meteorological department data.
Historical Met data shows that 2015 was the hottest year of the past four, having posted an average annual temperature of 22.82 °C followed by 2016 at 22.76 °C and 2017 which closed at an average temperature of 22.05 degrees Celsius.
Lodwar in Turkana continues to post the highest temperature in the country, with an average of 31.5 degrees Celsius. This, however, is lower than the previous three years, consistent with the national temperature drop.
The lowest temperatures were recorded at the Nyahururu weather station, at an average of 22.1 degrees, compared to the 22.8 in 2016. It was relatively hotter from January to June as compared to the 21.7 long term mean for the year.
Kenya registering a cool 2018, however, seems to have been out of tune with the global weather chart, which captured the year as the hottest on record. This sets the world on a steady path towards recording the warmest decade in history.
A report published last week by the World Meteorological Organisation found that global average surface temperature in 2018 was approximately 1.0° Celsius above the pre-industrial baseline of 1850-1900, making 2018 the fourth warmest on record.
“The long-term temperature trend is far more important than the ranking of individual years, and that trend is an upward one,” said WMO secretary-general Petteri Taalas, during the launch of the report in Geneva.
“The 20 warmest years on record have been in the past 22 years. The degree of warming during the past four years has been exceptional, both on land and in the ocean.”
The rising temperatures triggered a series of extreme weather events around the globe, and by the end of year, more than 5,000 people were dead and 29 million others affected.
“Temperatures are only part of the story. Extreme and high-impact weather affected many countries and millions of people, with devastating repercussions for economies and ecosystems in 2018,” said Mr Taalas.
One of the deadliest climate-related natural disasters of 2018 took place in the coastal Indian state of Kerala. Flooding in August claimed the lives of 361 people and left hundreds of thousands completely stranded or homeless.
Asia has in the past been extremely vulnerable to extreme weather, and a study published this year by the World Bank suggests that climate change is already affecting more than 800 million people living in south Asia, and the situation will get worse in the future.
In the same year, floods swept through Nigeria, leaving destruction, death and despair in its wake.
Nearly 200 people across 10 states are reported to have died in the September flood, leading the country to declare a national disaster.
Algeria posted its hottest temperature yet when the town of Ouargla hit an average of 51.3 degrees Celsius on July 5.
It has been argued that this could be the hottest average temperature ever recorded on the African continent, but previous WMO data has indicated that the hottest weather was posted in Kebili, Tunisia on July 7, 1931, at 55 degrees Censius. Some scientists, however, have discredited the Tunisia reading, citing credibility.
In July, Japan declared a national disaster after an unprecedented heat wave killed 65 people within a week, and left more than 22,647 others hospitalised.
Japan’s summers are notoriously hot and humid, and hundreds of people die each year from heatstroke, particularly the elderly.
The heatwave came right after record rainfall caused flooding and landslides in western and central Japan killing more than 220 people.
Within the year, a severe drought hit Argentina, the worst in 30 years, affecting grain prices on the global market. Argentina is the world’s third-largest exporter of maize and soya beans. The Buenos Aires Grain Exchange reported that the country’s economy suffered 3.5 billion dollars in losses as a result.
In Europe, there was a freezing weather at one time. A strong blast of cold air from Siberia caused blizzards to sweep through Europe at the end of February and beginning of March. Nicknamed the ‘Beast from the East’ in the UK, the cold front caused unusually low temperatures across the continent.
The effects were deadly, particularly for homeless people.
In Poland, 23 people died. It has been argued that the Beast from the East was nothing more than just a freak occurrence and completely unrelated to climate change, but scientists say it may have been caused by a weakening of the polar vortex as a result of global warming. In 2018, the US experienced 14 weather and climate disasters, each with losses exceeding $1 billion, all totalling $91 billion in damages.
Both the number of events and their cumulative cost ranked fourth highest since records began in 1980.
“Many of the extreme weather events are consistent with what we expect from a changing climate. This is a reality we need to face up to. Greenhouse gas emission reduction and climate adaptation measures should be a top global priority,” said Mr Taalas.
In the same year, atmospheric carbon dioxide concentration levels rose to 411 parts per million, the highest the world has seen in 800,000 years.
The only other time that carbon dioxide was this high was more than three million years ago, when temperature was between 2° and 3°C, higher than during the pre-industrial era.
Scientists say carbon dioxide concentrations are rising mostly because of burning fossil fuels for energy.
In the 1960s, the global growth rate of atmospheric carbon dioxide was roughly 0.6 ± 0.1 ppm per year. But over the past decade, the growth rate has been closer to 2.3 parts per million per year.
Warmed by sunlight, the earth’s land and ocean surfaces continuously radiate thermal infrared energy.
Unlike oxygen or nitrogen — that makes up most of the atmosphere— greenhouse gases absorb that heat and releases it gradually over time, like bricks in a fireplace after the fire goes out.
Without this natural greenhouse effect, the earth’s average annual temperature would be below freezing instead of close to 60°F.
But increases in greenhouse gases have tipped the Earth's energy budget out of balance, trapping additional heat and raising earth's average temperature. Increases in atmospheric carbon dioxide are responsible for about two-thirds of the total energy imbalance that is causing the earth's temperature to rise.
Kenya experienced heavy rainfall in the long rains season that caused countrywide flooding, deaths and destruction, barely a year after suffering a severe drought.
And while the 2017 drought resulted in Kenya putting forth a United Nations appeal for help, the 2008-2011 drought is still considered one of the worst in the country’s history, costing the economy more than Sh100 billion in losses.
And with 2019 now in its second month, the global warming trend still continues, with Tasmania in Australia reporting its driest January on record, resulting in wildfires.
As Australia suffocates in heat, parts of North America are reporting extremely cold temperatures, the lowest on record.
Already, the Intergovernmental Panel on Climate Change has warned that the world has only 12 years left to get reverse global warming, before the impacts of climate change become disastrous.
This means that the risk and impact of droughts, floods and extreme temperatures will be worse over the next few years as the earth continues to heat.