CLIMATE change, a defining challenge of our era, is the long-term alteration of temperature and typical weather patterns in a place. This phenomenon, primarily driven by human activities, has far-reaching consequences for the environment and society.
The pursuit of convenience and modern lifestyles has significantly contributed to the acceleration of climate change. From the industrial revolution to the digital age, human ingenuity has led to remarkable advancements, but these achievements often come with hidden environmental costs.
Fossil fuel consumption, deforestation, industrial emissions, and excessive waste are byproducts of our quest for convenience, and they have collectively intensified the greenhouse effect, leading to global warming.
Understanding the intricate relationship between human convenience and climate change is crucial for developing sustainable solutions and mitigating the adverse effects on our planet.
Climate change a hoax?
Lourdes Tibig, Climate Science Advisor of the Institute for Climate and Sustainable Cities, said that climate change is a natural process within the climate system, such as changes in the ocean's circulation.
However, despite experiencing its impact, Tibig said that it is quite alarming that some still don't believe in it.
"I don't know na marami 'yun ang hindi naniniwala sa climate change. They say that this climate change that we're talking about is a hoax," she said.
"Because they say climate has been changing through the years. It's true," she said, adding the sun's intensity and the slow changes in the earth's orbit around the sun have been natural factors for climate change.
However, the earth is already millions of years older and has been experiencing a huge change in its climate due to human interference, the expert added.
Greenhouse gasses
Greenhouse gasses (GHGs) are atmospheric gasses that trap heat within the Earth's atmosphere, contributing to the greenhouse effect. This effect is crucial for maintaining the planet's temperature and supporting life, but an excess of these gasses can lead to global warming and climate change.
Carbon dioxide (CO₂) is a colorless, odorless gas that is naturally present in the Earth's atmosphere. It is composed of one carbon atom and two oxygen atoms. While CO₂ is a vital part of the planet's carbon cycle and essential for processes such as photosynthesis in plants, its concentration in the atmosphere has significantly increased due to human activities.
"If you run your car, you use gasoline. The moment you switch on your car engine, carbon dioxide is emitted. They are not visible to the naked eye, but [it] is just there," Tibig said.
The average lifetime of carbon dioxide is hundreds to thousands of years with about 25 percent lasting forever.
Human activities are being cited as the cause of the increase in the concentration of greenhouse gasses.
Human-induced activities such as the burning of fossil fuels, transport, and industries are one of them.
Human activities that change land surface such as deforestation, reforestation, and urbanization, are also to blame.
Methane (CH₄) is a potent greenhouse gas with significant implications for climate change. Though it is present in smaller quantities than carbon dioxide (CO₂), it has a much higher capacity to trap heat in the atmosphere, making it a critical focus in efforts to mitigate global warming.
Tibig said that over a 20-year period, 1 metric ton of CH₄ can trap about 80 times that of 1 metric ton of CO₂.
"It means that methane can contribute to global warming 80 times compared to carbon dioxide," she said.
Other man-made sources of greenhouse gasses are nitrous oxide (N₂O), and natural sources including bacterial breakdown of nitrogen in soils and ocean, while man-made sources include the use of chemical-based fertilizers and pesticides in agriculture, biomass burning, combustion process in vehicles, and acid production.
In terms of average lifetime for about 110 years, over a 20-year period, one metric ton of N₂O can trap as much as about 273 times that of one metric ton of CO₂.
Other man-made sources of greenhouse gasses, which also contribute to climate change, are hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6), which are present in refrigerators.
"(The) Worst part of it is the average lifetime is from 52 to 93 years. Over a 20-year period, one metric ton of CFCs can trap as much as thousands to tens of thousand times that of one metric ton of CO₂,” she said.
Tibig added that CO₂ can cause warming as it absorbs some of the heat radiation coming off Earth's sunbaked surface and reradiates it downward.
Four-fifths of CO₂ emissions come from burning fossil fuels. Nearly all the rest come from deforestation and other changes in land use.
Even at the current emissions rate, CO₂ is released into the atmosphere nearly twice as fast as it is removed.
But where do CO₂ go? The expert said that plants and soil absorb about a third each year, and ocean surface waters about a quarter. The rest of the 45 percent stays airborne for a long time.
When asked if CO₂ has been this high before, she said it is not for at least 800,000 years, say the oldest air bubbles found in Antarctic ice cores — and probably not for millions of years.
But how much is too much?
"No one is sure. Some scientists think we need to reduce the CO₂ level back down to 350 parts per million (ppm) — equivalent to 745 billion metric tons of carbon — to avoid serious climate impacts," she said.
"But if current emissions trends continue, 450 ppm will be passed well before the mid-century," she added.
Therefore, human activities are making the "blanket”, which traps the heat and causes the enhanced greenhouse effect, thicker.
As compared to the natural greenhouse effect, the earth is covered by a blanket of gasses which allows energy from the sun to reach the Earth's surface, where some of it is converted into heat energy. Most of the heat is re-radiated towards the ground by greenhouse gasses in the atmosphere. This is a natural effect that keeps the Earth's temperature at a level necessary to support life.
But because of human activities, greater concentrations of greenhouse gasses will trap more heat and raise the Earth's surface temperature.
Humans warmed the planet
Tibig said that global temperatures have been getting warmer for the last 65 million years, and would possibly get warmer depending on the amount of greenhouse gasses being emitted.
Citing the Intergovernmental Panel on Climate Change (IPCC) by the United Nations, human influence has warmed the climate at a rate that is unprecedented in at least the last 2,000 years.
She said that there has been a change in global surface temperature as observed and simulated using human and natural, and only natural factors between the years 1850 and 2020.
"The analysis of our climate scientist shows that in 1950, there has been a slight increase in temperatures becoming faster as we approach the year 2000," Tibig said.
IPCC reported that human activities affect all the major climate system components, with some responding over decades and others over centuries.
At the most recent assessment, it was in 2016 that the temperature increased worldwide by about 1.1 degrees Celsius.
Meanwhile, the global surface temperature change was measured through Shared Socioeconomic Pathways (SSPs). It is a socioeconomic-based scenario that specifies pathways to qualify and quantify factors of future population, economic growth, education, urbanization, and the rate of technological development and combines the mitigation targets of Representative Concentration Pathways (RCPs).
Unless actions are made, anthropogenic climate change will further cause impact.
She said these extreme weather events include tropical cyclones and river floods, which can reduce the economic growth of affected countries for more than a decade.
"For instance, during the period 1971-2014 and across all affected countries, growth losses from severe tropical cyclones and river floods may have accumulated to 6.5 percent and five percent, respectively, over 15 years," Tibig said.
The ongoing intensification of extreme weather in frequency and intensity due to climate change may therefore substantially reduce the development prospects of disaster-prone developing countries.
For the Philippines, tropical cyclones affect poorer populations disproportionately. Food-poor households in the country are significantly affected by the negative impacts on wage earnings, particularly from agricultural salaries as well as reduction in total food and non-food expenditures, suggesting limited resources to cope with income losses.
On PH's sea level rise
Tibig said that sea level rise results from the melting of sea ice covers, including ice sheets and glaciers in the polar regions, and thermal expansion of the seas and oceans as these warm.
Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) has observed that the sea level rise in the Philippines is higher than the global rate.
In a 2018 report, Pagasa said that over certain parts of the country, sea level rise had been more than double the global rate during the period of 1993 to 2015.
More recent projections (in particular, that by Climate Central) showed estimates of flood water depths in areas near the coasts at global warming of 1.5 degrees Celsius (°C) are higher than the projections indicated.
What can we do?
Tibig said that while the impact has been alarming throughout the year, she is firm in saying that there is more that needs to be done to prevent the Earth from getting warmer.
She said the ultimate goal of limiting temperature increase is by only 1.5°C within the 21st century. It can be done, however the window of opportunity is narrowing.
"It is not too late yet; we must act now and do deeper cuts in greenhouse gasses emissions," she said. RGL