Sharp rises in levels of methane

Sharp rises in levels of methane – which is a powerful greenhouse gas – have strengthened over the past four years. 

Some researchers believe the spread of intense farming in Africa may be involved, in particular in tropical regions where conditions are becoming warmer and wetter because of climate change. 

Rising numbers of cattle – as well as wetter and warmer swamps – are producing more and more methane, it is argued. 

If nothing can be done about the rise in methane levels, then even more cuts will have to be made in CO2 emissions. 

Production in the Indus Valley Civilization..

Agrarian base

A stable system of agriculture, supplemented by animal husbandry, hunting and plant gathering, provided economic sustenance to urban networks.

Well at Indus Valley Civilisation site, Rupnagar,
Punjab / Harvinder Chandigarh / CC-BY-SA 4.0

A ploughed field was revealed through excavation at Kalibangan. The Kalibangan field contained two sets of furrows crossing each other at right angles, thus forming a grid pattern, and it is likely that two crops were raised in the same field. In modern fields in that zone, mustard is grown in one set of furrows and horse gram in the other. Mixed cropping is suggested by other evidence as well as, for instance, in the mixture of wheat and barley at Indus sites. Such mixed cropping is practiced even today in many parts of north India as an insurance against weather hazards so that if wheat fails to ripen, the hardier barley is sure to yield a crop.

Cultivated crops included wheat, barley, rice, millets, peas, lentils, chickpeas, sesame, flax, legumes and cotton. Cattle meat was the favourite animal food of the Indus people and cattle bones have been found in large quantities at all sites that have yielded bones. In addition to their meat, cattle and buffaloes must have supported agricultural operations and served as draught animals. Mutton was also popular and bones of sheep/goat have been found at almost all Indus sites. Hunting of animals was also carried out. 

Manufacturing and Trade

Bullock cart, 2000 BC / Yann / CC-BY-SA 4.0

Inhabitants of the ancient Indus River Valley developed new techniques in metallurgy—the science of working with copper, bronze, lead, and tin. Harappans also made intricate handicrafts using semi-precious gemstone Carnelian. They worked on shells, and shells used in their crafts have origins from as far away as the coast of modern-day Oman.

Several constructions have been identified as workshops or industrial quarters and some of the buildings might have been warehouses. An Impressive workshop, recognized as Bead Making Factory, was found at Channu Daro city, which included a furnace. Shell bangles, beads of many materials, stealite seals and metal works were also manufactured at Channu Daro. Harappan seals were made generally in bigger towns which were involved with administrative network.

Statue production, and skilled metal working (in both bronze and precious metals) has been uncovered in Rakhigarhi. A gold foundry with about 3000 unpolished semi-precious stones has been found here.

Mold of Seal, Indus valley civilization, 2500 BC
Ismoon / CC-BY-SA1.0

Signs of flourishing trade can be seen by the excavation of stamps, jewellery and 'chert' weights. 

Trade focused on importing raw materials to be used in Harappan city workshops, including minerals from Iran and Afghanistan, lead and copper from other parts of India, jade from China, and cedar wood floated down rivers from the Himalayas and Kashmir. Other trade goods included terracotta pots, gold, silver, metals, beads, flints for making tools, seashells, pearls, and colored gemstones, such as lapis lazuli and turquoise.

Birds & Ecosystem Services

Attribution: Andrew Butko / CC-BY-SA 3.0

Everyone in the world depends completely on Earth’s ecosystems and the services they provide, such as food, water, disease management, climate regulation, spiritual fulfillment, and aesthetic enjoyment. 

Studies have sought to examine the services provided by birds in the ecosystems they inhabit.

Birds encourage more and healthier plant growth by the spread of their poop which is an excellent additive to any fertilizer. By spreading activities through different habitats, birds can move nutrients from one place to another, which is particularly relevant in places where plant growth is limited by nutrient availability. A study on the islands in the Gulf of California showed that when birds roosted on them, the guano deposits they left behind provided nutrients to plants on the island. As a result, islands with seabirds had plants that grew taller and faster and were much more productive than those on islands without birds.

Utkarsh22december / CC-BY-SA 4.0

Wetlands are considered one of the most valuable habitats, providing an array of important services like shoreline stabilization and water filtration. In the southeastern United States, snails can overgraze the grasses in salt marshes and completely convert a productive marsh into mudflats. Several species of birds such as oystercatchers, curlews, and plovers are predators of these snails and control their numbers, which regulates primary productivity of salt marshes.

Waterbirds play key functional roles in many aquatic ecosystems, including as predators, herbivores and vectors of seeds, invertebrates and nutrients. Waterbirds can maintain the diversity of other organisms, control pests, be effective bio-indicators of ecological conditions, and act as sentinels of potential disease outbreaks. They also provide important provisioning (meat, feathers, eggs, etc.) and cultural services to both indigenous and westernized societies. 

Apple Blossom @ Manali, India / Sanu N / CC-BY-SA 4.0

The construction of nest boxes for great tits in apple orchards has been shown to lead to greater numbers of birds in the area, which forage on caterpillars that can cause damage to crops, resulting in significantly higher crop yields. Similarly, the use of artificial perches for raptors around agricultural fields may increase the number of raptors that prey on rodents that can cause damage to crops. If installed and maintained properly, the construction of bird nest boxes can eliminate the need for pesticides, saving farmers money and preventing potentially dangerous chemicals from being applied.

Buffalos and crane birds, Chinawal village, India / ABHIJEET / CC-BY-SA 3.0

Many birds perch on livestock like cattle and forage on insects that live on them. Cattle egrets are particularly well known for making a living this way. When infested with ticks, cows can become anemic and milk production flags. In Pakistan, birds are capable of effectively preying on these parasites, leading to healthier and more productive cows. This predation by birds is even more effective than pesticides in some cases.

Scavenging by birds is an important mechanism of waste disposal in many areas and prevents the outbreak of diseases than can occur through the accumulation of animal carcasses. In India, declines in vultures led to increases in feral dogs as there was less competition for carrion as a food source. The explosion of the dog population led to increases in rabies outbreaks and human injuries from dog attacks. The total estimated health cost of vulture declines between 1993 and 2006 is a whopping $34 billion.

KostasGiannakis / CC-BY-SA 4.0

Another way that birds can provide regulating services is through promoting forest growth. When birds pick a seed or fruit from a plant and fly off with it, they end up transporting the seed to another place where it can germinate. This behavior is a major mechanism for seed dispersal in many plants and can increase the genetic diversity of plants in a particular area by spreading seeds. By germinating the seeds of trees, birds can contribute to the reforesting of deforested lands, diminishing the costs of restoration. In oak forests in Sweden, the cost of replacing the seed dispersal services of Eurasian jays in oak regeneration is an estimated $9,400 per hectare

Finally, cultural services by birds include spiritual enrichment, companionship, music and the appreciation of nature.

Acknowledgement : The blog post above is largely an edited version of this article.