Author: Santosh Koirala

About Santosh Koirala

Santosh Koirala is an agriculture student at the Agriculture and Forestry University, Rampur, Nepal.

Drylands will suffer if world reaches 2°C

Drylands Burkina Faso woman cart delivering firewood

Subtropical drylands heat up far quicker than humid climates, so the global temperature must be kept below the 2°C target to avoid serious consequences.

KATHMANDU, 25 April, 2017 – In what may be good news only for cactus, termites and drought-resistant grasses, subtropical dry areas are going to expand over large parts of the Earth as the climate warms.

This will seriously reduce the amount of land that can be used to grow crops for human consumption and prevent many deeper-rooted shrubs and trees from growing at all.

This latest finding in Nature Communications is a surprise because it had been assumed that deep-rooted woody plants would survive better in subtropical dry areas because they would be able to extract moisture from far below ground.

Deep soils

However, scientists discovered that these deep soils dried out and stayed dry for longer periods because the moisture from the rains evaporated or was used by shallow-rooted plants before it could percolate down to the subsoil.

Groups of scientists studied vast areas of land in North and South America, Asia, Southern Africa and the Western Mediterranean basin. They found that temperate drylands reduced in size by about one-third but only because they morphed into subtropical drylands as temperature rose. Absence of frost from temperate drylands enabled subtropical plants and insects to invade them.

The paper says these impacts “could have large consequences for human wellbeing: aggressive human diseases, including dengue and schistosomiasis, as well as mound-building termites, occur in subtropical climates and could expand as temperate drylands warm, whereas cool season crops such as wheat and potato would no longer be economically viable”.

All areas, except for some parts of East Asia and North America, had fewer wet days and longer meteorological droughts. As a result, shallow soils lost on average an extra seven days’ growing season while subsoils, below 20cm, lost another 22 days.

Degradation and desertification will become
a challenge to the global ecosystem and
human survival in the near future”

These extra periods of drought will have a serious effect on the varieties of plants that can grow in these areas, with much existing vegetation dying off and an increase in the number of wildfires. Areas such as the Mediterranean where currently it is possible to grow wheat and potatoes in the spring before the summer heat arrives, will no longer have enough soil moisture available for growing food crops, the paper says.

Since these global drylands extend over 40% of the Earth’s surface, an increase in their size will affect millions of people who currently live in them or at their margins. The scientists say that measures need to be taken now to reduce the impact of drought in these highly populated regions, because their research shows that there will be a major shift in vegetation and the ability to grow food.

Extended drought due to enhanced warming and rapid population growth pose major threats to the people living in the drylands,” says atmospheric scientist Jianping Huang at Lanzhou University in China. “Degradation and desertification will become a challenge to the global ecosystem and human survival in the near future.”

By the end of the century, changes in evaporation due to warming, and changes in rainfall patterns, will mean an extension of drylands to 56% of the Earth’s surface. Apart from human welfare, the number and diversity of plant and animal species that can survive in these areas will diminish, and soil conservation and carbon storage is also likely to suffer. Increasing drylands due to global warming will reduce the soil organic carbon storage, resulting in emission of CO2 into the atmosphere.

Target for drylands

In a new paper in Nature Climate Change, Huang and colleagues report that they have discovered that drylands heat up 44% more than humid climates. This means a lower target than 2°C is required to avoid serious consequences for drylands.

He says: “Decreased maize yields and runoff, increased long-lasting drought and more favourable conditions for malaria transmission are greatest over drylands if the global warming were to rise from 1.5°C to 2.0°C.

Strict management and rational utilisation of water resources, along with the restoration of soils and vegetation to reduce ecosystem vulnerability on a global scale are urgently needed to develop a global action plan to prevent future desertification and eradicate present desertification problems.”
– Climate News Network

Subtropical drylands heat up far quicker than humid climates, so the global temperature must be kept below the 2°C target to avoid serious consequences.

KATHMANDU, 25 April, 2017 – In what may be good news only for cactus, termites and drought-resistant grasses, subtropical dry areas are going to expand over large parts of the Earth as the climate warms.

This will seriously reduce the amount of land that can be used to grow crops for human consumption and prevent many deeper-rooted shrubs and trees from growing at all.

This latest finding in Nature Communications is a surprise because it had been assumed that deep-rooted woody plants would survive better in subtropical dry areas because they would be able to extract moisture from far below ground.

Deep soils

However, scientists discovered that these deep soils dried out and stayed dry for longer periods because the moisture from the rains evaporated or was used by shallow-rooted plants before it could percolate down to the subsoil.

Groups of scientists studied vast areas of land in North and South America, Asia, Southern Africa and the Western Mediterranean basin. They found that temperate drylands reduced in size by about one-third but only because they morphed into subtropical drylands as temperature rose. Absence of frost from temperate drylands enabled subtropical plants and insects to invade them.

The paper says these impacts “could have large consequences for human wellbeing: aggressive human diseases, including dengue and schistosomiasis, as well as mound-building termites, occur in subtropical climates and could expand as temperate drylands warm, whereas cool season crops such as wheat and potato would no longer be economically viable”.

All areas, except for some parts of East Asia and North America, had fewer wet days and longer meteorological droughts. As a result, shallow soils lost on average an extra seven days’ growing season while subsoils, below 20cm, lost another 22 days.

Degradation and desertification will become
a challenge to the global ecosystem and
human survival in the near future”

These extra periods of drought will have a serious effect on the varieties of plants that can grow in these areas, with much existing vegetation dying off and an increase in the number of wildfires. Areas such as the Mediterranean where currently it is possible to grow wheat and potatoes in the spring before the summer heat arrives, will no longer have enough soil moisture available for growing food crops, the paper says.

Since these global drylands extend over 40% of the Earth’s surface, an increase in their size will affect millions of people who currently live in them or at their margins. The scientists say that measures need to be taken now to reduce the impact of drought in these highly populated regions, because their research shows that there will be a major shift in vegetation and the ability to grow food.

Extended drought due to enhanced warming and rapid population growth pose major threats to the people living in the drylands,” says atmospheric scientist Jianping Huang at Lanzhou University in China. “Degradation and desertification will become a challenge to the global ecosystem and human survival in the near future.”

By the end of the century, changes in evaporation due to warming, and changes in rainfall patterns, will mean an extension of drylands to 56% of the Earth’s surface. Apart from human welfare, the number and diversity of plant and animal species that can survive in these areas will diminish, and soil conservation and carbon storage is also likely to suffer. Increasing drylands due to global warming will reduce the soil organic carbon storage, resulting in emission of CO2 into the atmosphere.

Target for drylands

In a new paper in Nature Climate Change, Huang and colleagues report that they have discovered that drylands heat up 44% more than humid climates. This means a lower target than 2°C is required to avoid serious consequences for drylands.

He says: “Decreased maize yields and runoff, increased long-lasting drought and more favourable conditions for malaria transmission are greatest over drylands if the global warming were to rise from 1.5°C to 2.0°C.

Strict management and rational utilisation of water resources, along with the restoration of soils and vegetation to reduce ecosystem vulnerability on a global scale are urgently needed to develop a global action plan to prevent future desertification and eradicate present desertification problems.”
– Climate News Network

Himalayan bloom brings spring forward

Himalayan rhododendron

The flowering season of the Himalayan rhododendron has moved forward by three months in response to climate change.

RANPUR, Nepal, 2 January, 2017 – The rhododendron, one of the most popular and colourful small evergreen trees grown in gardens and parks across the world, is changing its flowering season from spring to winter in its native Himalayan habitat.

The blooming of rhododendron, with their conspicuous displays of deep red or pale pink flowers, has always heralded the arrival of spring in the Himalayas, but this has undergone a dramatic change. Peak flowering season is now early February to mid-March, instead of the spring months from March to May.

A group of scientists at the GB Pant Institute of Himalayan Environment and Sustainable Development in Almora, India, studied the change in flowering times of the native Rhododendron arboreum to see if they could relate it to climate change.

Temperature data

They report in Research Communications journal that they analysed the long-term temperature data of the region for the previous 40 years (1971-2011) and found a comparatively small but significant increase in mean maximum temperature of 0.5°C over the period.

Using real time observations in three seasons, 2009 to 2011, and long-term herbarium records from 1893 to 2003, the scientists concluded that the peak flowering of the tree had moved forward three months – by between 88 and 97 days, depending on the recording site.

“The present field observations over three years
revealed a considerably higher frequency
of bloom during February-March”

This was the most dramatic advance in flowering times of local plants studied. Another species, Aconitum heterophyllum, is highly prized for its tubers for use in Indian medicine − for example, for cough remedies and to treat diarrhoea and indigestion. It occupies much of the same terrain, but has advanced its flowering period by only 17-25 days over the same period.

Dr Ranbeer S Rawal, who led the research, says alterations in the phenological activity of organisms had been shown by science to be the result of unusually warm temperatures, caused by human-induced climate change.

Phenology is the study of the times of recurring natural events, especially in relation to climate. The phenological responses of plants, particularly early flowering, are considered important biological indicators of climate change, and the rhododendron results were among the most dramatic.

Himalayan range

“The present field observations over three years revealed a considerably higher frequency (47%-75 % trees) of bloom during February-March, which provides a strong basis to prove other observational reports of advancement in flowering events of target species from spring to winter,” Dr Rawal says.

The report concludes that the study’s findings provide an important insight into species response to climate change in India’s central Himalayan mountain range. It highlights the need for further research on the subject to improve our understanding of the effects of climate change on species, and consequently on the ecology of the region.

“The trends definitely warrant attention as an indicator of climate change impacts on the flowering phenology of prominent regional species, and the likely consequences for ecosystem processes,” Dr Rawal adds. – Climate News Network

The flowering season of the Himalayan rhododendron has moved forward by three months in response to climate change.

RANPUR, Nepal, 2 January, 2017 – The rhododendron, one of the most popular and colourful small evergreen trees grown in gardens and parks across the world, is changing its flowering season from spring to winter in its native Himalayan habitat.

The blooming of rhododendron, with their conspicuous displays of deep red or pale pink flowers, has always heralded the arrival of spring in the Himalayas, but this has undergone a dramatic change. Peak flowering season is now early February to mid-March, instead of the spring months from March to May.

A group of scientists at the GB Pant Institute of Himalayan Environment and Sustainable Development in Almora, India, studied the change in flowering times of the native Rhododendron arboreum to see if they could relate it to climate change.

Temperature data

They report in Research Communications journal that they analysed the long-term temperature data of the region for the previous 40 years (1971-2011) and found a comparatively small but significant increase in mean maximum temperature of 0.5°C over the period.

Using real time observations in three seasons, 2009 to 2011, and long-term herbarium records from 1893 to 2003, the scientists concluded that the peak flowering of the tree had moved forward three months – by between 88 and 97 days, depending on the recording site.

“The present field observations over three years
revealed a considerably higher frequency
of bloom during February-March”

This was the most dramatic advance in flowering times of local plants studied. Another species, Aconitum heterophyllum, is highly prized for its tubers for use in Indian medicine − for example, for cough remedies and to treat diarrhoea and indigestion. It occupies much of the same terrain, but has advanced its flowering period by only 17-25 days over the same period.

Dr Ranbeer S Rawal, who led the research, says alterations in the phenological activity of organisms had been shown by science to be the result of unusually warm temperatures, caused by human-induced climate change.

Phenology is the study of the times of recurring natural events, especially in relation to climate. The phenological responses of plants, particularly early flowering, are considered important biological indicators of climate change, and the rhododendron results were among the most dramatic.

Himalayan range

“The present field observations over three years revealed a considerably higher frequency (47%-75 % trees) of bloom during February-March, which provides a strong basis to prove other observational reports of advancement in flowering events of target species from spring to winter,” Dr Rawal says.

The report concludes that the study’s findings provide an important insight into species response to climate change in India’s central Himalayan mountain range. It highlights the need for further research on the subject to improve our understanding of the effects of climate change on species, and consequently on the ecology of the region.

“The trends definitely warrant attention as an indicator of climate change impacts on the flowering phenology of prominent regional species, and the likely consequences for ecosystem processes,” Dr Rawal adds. – Climate News Network

Rice paddies raise methane threat

Traditional growing of rice in flooded fields is bad for the staple crop’s future quality and produces vast amounts of methane greenhouse gas.

RAMPUR, Nepal, 10 September, 2016 − Directly seeding rice into fields rather than transplanting it into flooded paddies would dramatically reduce methane emissions and slow down climate change, according to scientists studying the staple crop.

A number of experiments in Asia, particularly in the Philippines and Japan, show that a change in the way rice is grown would have considerable other benefits in saving water and improving yield. However, in Asia, which accounts for 90% of rice production, only a quarter of the crop is currently produced by direct seeding.

The research, cited by the UN Food and Agriculture Organisation, says that while rice is a staple food for more than half the world’s population, growing it is becoming less profitable because of the costs of labour, shortage of water and high energy costs.

The research paper says that the present practice of tillage and planting in flooded rice paddies – known as puddling − damages the soil and affects the quality of future crops. This, plus the need to cut methane emissions, “demands a major shift from puddled transplanting to direct seeding of rice”.

Without changes, the world has no hope of reaching the extra 100 million tons of rice yield that it is estimated will be needed by 2035 – an increase of 25% on current crops.

Manmade emissions

Methane is the second major greenhouse gas, after carbon dioxide, and agriculture accounts for 40% of these emissions. Although farm animals are a major source, flooded rice paddies emit as much as 500 million tons, which is around 20% of total manmade emissions of this gas.

The Intergovernmental Panel on Climate Change has estimated that rice cultivation is a major contribution to global warming. When rice is grown under puddled transplanted conditions, paddy soil becomes anoxic − depleted of dissolved oxygen − and then, in the absence of oxygen, microbes that break down plant matter produce methane.

“Considering the effectiveness of direct seeding of rice to reduce the methane emission, it is imperative that it be promoted throughout Asia”

Flooded soil may trap large quantities of methane, and this then escapes into the atmosphere during wet tillage, harrowing, transplanting and weeding. Rice plants themselves also have a system of releasing methane through their leaves called methanogenesis. The rest escapes either by bubbling upwards or when the soil finally dries out.

Although not all rice is grown in flooded conditions, 90% of rice land globally is at least temporarily flooded. On average, the soil is fully waterlogged for about four months each year.

The research shows that direct seeded rice has a shorter flooding period (roughly a month) that ensures there is oxygen in the soil through most of the rice season. There is also decreased soil disturbance compared to transplanted rice seedlings.

Decreased methane

Thus, direct seeding is an effective technique to decrease the methane gas emissions otherwise released from the conventional puddled transplanted rice fields.

Jagdish K Ladha, principal scientist for soils and agronomy research at the International Rice Research Institute in New Delhi, says direct seeding of rice always reduces methane emissions from the crop and can be up to 90%, but that depends on methods used and the water management system.

A field experiment in the Philippines showed that the direct seeding techniques reduced methane emissions by 18% as compared with transplanted rice. Another study, in Japan, showed that global warming potential declined by 42% just by changing puddling of rice seedlings to zero tillage.

“Considering the effectiveness of direct seeding of rice to reduce the methane emissions, compared to the conventional rice transplanting technique, it is imperative that it be promoted throughout Asia,” Ladha says. – Climate News Network

  • Santosh Koirala is a student of agriculture at the Agricultural and Forestry University in Rampur, Nepal.

Traditional growing of rice in flooded fields is bad for the staple crop’s future quality and produces vast amounts of methane greenhouse gas.

RAMPUR, Nepal, 10 September, 2016 − Directly seeding rice into fields rather than transplanting it into flooded paddies would dramatically reduce methane emissions and slow down climate change, according to scientists studying the staple crop.

A number of experiments in Asia, particularly in the Philippines and Japan, show that a change in the way rice is grown would have considerable other benefits in saving water and improving yield. However, in Asia, which accounts for 90% of rice production, only a quarter of the crop is currently produced by direct seeding.

The research, cited by the UN Food and Agriculture Organisation, says that while rice is a staple food for more than half the world’s population, growing it is becoming less profitable because of the costs of labour, shortage of water and high energy costs.

The research paper says that the present practice of tillage and planting in flooded rice paddies – known as puddling − damages the soil and affects the quality of future crops. This, plus the need to cut methane emissions, “demands a major shift from puddled transplanting to direct seeding of rice”.

Without changes, the world has no hope of reaching the extra 100 million tons of rice yield that it is estimated will be needed by 2035 – an increase of 25% on current crops.

Manmade emissions

Methane is the second major greenhouse gas, after carbon dioxide, and agriculture accounts for 40% of these emissions. Although farm animals are a major source, flooded rice paddies emit as much as 500 million tons, which is around 20% of total manmade emissions of this gas.

The Intergovernmental Panel on Climate Change has estimated that rice cultivation is a major contribution to global warming. When rice is grown under puddled transplanted conditions, paddy soil becomes anoxic − depleted of dissolved oxygen − and then, in the absence of oxygen, microbes that break down plant matter produce methane.

“Considering the effectiveness of direct seeding of rice to reduce the methane emission, it is imperative that it be promoted throughout Asia”

Flooded soil may trap large quantities of methane, and this then escapes into the atmosphere during wet tillage, harrowing, transplanting and weeding. Rice plants themselves also have a system of releasing methane through their leaves called methanogenesis. The rest escapes either by bubbling upwards or when the soil finally dries out.

Although not all rice is grown in flooded conditions, 90% of rice land globally is at least temporarily flooded. On average, the soil is fully waterlogged for about four months each year.

The research shows that direct seeded rice has a shorter flooding period (roughly a month) that ensures there is oxygen in the soil through most of the rice season. There is also decreased soil disturbance compared to transplanted rice seedlings.

Decreased methane

Thus, direct seeding is an effective technique to decrease the methane gas emissions otherwise released from the conventional puddled transplanted rice fields.

Jagdish K Ladha, principal scientist for soils and agronomy research at the International Rice Research Institute in New Delhi, says direct seeding of rice always reduces methane emissions from the crop and can be up to 90%, but that depends on methods used and the water management system.

A field experiment in the Philippines showed that the direct seeding techniques reduced methane emissions by 18% as compared with transplanted rice. Another study, in Japan, showed that global warming potential declined by 42% just by changing puddling of rice seedlings to zero tillage.

“Considering the effectiveness of direct seeding of rice to reduce the methane emissions, compared to the conventional rice transplanting technique, it is imperative that it be promoted throughout Asia,” Ladha says. – Climate News Network

  • Santosh Koirala is a student of agriculture at the Agricultural and Forestry University in Rampur, Nepal.

Renewables fuel optimism in Nepal

Cattle dung and kitchen waste used in biogas plants are helping to save 400,000 trees a year and reduce fossil fuel imports in Nepal.

RAMPUR, 24 June, 2016 – More than a million extra small biogas plants in Nepal could stop forest destruction and reduce the country’s large import bill for fossil fuels − but much more investment is needed to help the impoverished country reach its goals.

The government’s 2016 Renewable Energy Subsidy Policy is seeking to ramp up investments in power sources such as small-scale hydro, solar, wind and biomass,

One of the habits it is trying to break is the use of wood for cooking. Currently, 64% of the population, particularly the rural poor, rely on supplies of firewood to prepare their daily meal, causing the destruction of the country’s forests.

The whole programme has a significant way to go, because in 2012/13 renewables accounted for only 1.66% of the country’s total energy supply, according to the government’s Alternative Energy Promotion Centre (AEPC).

Major waste

The largest established form of renewables in this mountainous country is micro-hydropower, with 36 MW of electricity, but biogas also has great potential.

This is because the availability of dung − the major waste used for biogas production in rural areas − is calculated at 12 million tonnes a year, enough to fuel 1.49 million household biogas plants in Nepal. And the methane produced by each micro-plant is calculated to save 1.25 trees a year.

The use of readily-available materials – cattle dung and kitchen waste in rural areas, and sewage and kitchen waste in towns – could fuel a biogas boom to head off a looming energy crisis caused by the ever-increasing import of fossil fuels.

Lack of investment in larger-scale biogas plants
in urban areas has led to a surge in imports
of liquefied petroleum gas

The AEPC says that Nepal, through the use of the existing 320,000 biogas plants and the avoidance of cutting tree cover, is already reducing its overall greenhouse emissions by more than one million tons a year. This is saving 400,000 trees annually, and reducing natural gas imports from India.

A second study by the Biogas Sector Programme says that the biogas replaces 800,000 litres of kerosene.

Known potential

Unfortunately, despite its known potential, the lack of investment in larger-scale biogas plants in urban areas has led to a surge in imports of liquefied petroleum gas (LPG). This has now reached 21% of households.

Despite 670 tonnes of biodegradable waste being generated every day in 58 municipalities across the country, the total number of large-scale biogas plants is only 350. Lack of regular maintenance has led to some of these breaking down

The recently-announced government incentive to subsidise and provide loans to boost renewable energy should reduce this decline. The declared aim is to resuscitate and expand the renewable energy source that has already proved to be a realistic way of reining in the need for fossil fuels. – Climate News Network

  • Santosh Koirala is an agriculture student at the Agriculture and Forestry University (AFU), Rampur, Nepal.
    Email: Mezereonsantosh@gmail.com; Twitter: @mezereonsantos
  • Additional reporting by Sameer Pokhrel, also a student at AFU.
    Email: pokhrelsameer60@gmail.com; Twitter: @sameerpokhrel5

Cattle dung and kitchen waste used in biogas plants are helping to save 400,000 trees a year and reduce fossil fuel imports in Nepal.

RAMPUR, 24 June, 2016 – More than a million extra small biogas plants in Nepal could stop forest destruction and reduce the country’s large import bill for fossil fuels − but much more investment is needed to help the impoverished country reach its goals.

The government’s 2016 Renewable Energy Subsidy Policy is seeking to ramp up investments in power sources such as small-scale hydro, solar, wind and biomass,

One of the habits it is trying to break is the use of wood for cooking. Currently, 64% of the population, particularly the rural poor, rely on supplies of firewood to prepare their daily meal, causing the destruction of the country’s forests.

The whole programme has a significant way to go, because in 2012/13 renewables accounted for only 1.66% of the country’s total energy supply, according to the government’s Alternative Energy Promotion Centre (AEPC).

Major waste

The largest established form of renewables in this mountainous country is micro-hydropower, with 36 MW of electricity, but biogas also has great potential.

This is because the availability of dung − the major waste used for biogas production in rural areas − is calculated at 12 million tonnes a year, enough to fuel 1.49 million household biogas plants in Nepal. And the methane produced by each micro-plant is calculated to save 1.25 trees a year.

The use of readily-available materials – cattle dung and kitchen waste in rural areas, and sewage and kitchen waste in towns – could fuel a biogas boom to head off a looming energy crisis caused by the ever-increasing import of fossil fuels.

Lack of investment in larger-scale biogas plants
in urban areas has led to a surge in imports
of liquefied petroleum gas

The AEPC says that Nepal, through the use of the existing 320,000 biogas plants and the avoidance of cutting tree cover, is already reducing its overall greenhouse emissions by more than one million tons a year. This is saving 400,000 trees annually, and reducing natural gas imports from India.

A second study by the Biogas Sector Programme says that the biogas replaces 800,000 litres of kerosene.

Known potential

Unfortunately, despite its known potential, the lack of investment in larger-scale biogas plants in urban areas has led to a surge in imports of liquefied petroleum gas (LPG). This has now reached 21% of households.

Despite 670 tonnes of biodegradable waste being generated every day in 58 municipalities across the country, the total number of large-scale biogas plants is only 350. Lack of regular maintenance has led to some of these breaking down

The recently-announced government incentive to subsidise and provide loans to boost renewable energy should reduce this decline. The declared aim is to resuscitate and expand the renewable energy source that has already proved to be a realistic way of reining in the need for fossil fuels. – Climate News Network

  • Santosh Koirala is an agriculture student at the Agriculture and Forestry University (AFU), Rampur, Nepal.
    Email: Mezereonsantosh@gmail.com; Twitter: @mezereonsantos
  • Additional reporting by Sameer Pokhrel, also a student at AFU.
    Email: pokhrelsameer60@gmail.com; Twitter: @sameerpokhrel5