Agricultural waste released H+ to  the coastal and aquatic systems and decreases the pH leads to high CO2 emission resulting in global warming.

Dear @Ved Prakash

Agriculture is contributing a significant share of the greenhouse gas (GHG) emissions that are causing Global Warming as well as climate change – 17% directly through agricultural activities and an additional 7% to 14% through land use changes. For example, In our state, Bihar irrigation need are usually meet through diesel/kerosene based water pumps.These type of emissions share agricultural emissions, and  such emissions are expected to rise in the coming decades due to population and income growth, amongst other factors. Similarly, the agricultural sector, fertilizer application, livestock and manure management, rice cultivation, and savanna burning are the major sources of emissions. Since the answer to this question covers many aspects, I suggest you read IPCC, FAO and IARI  other reputed organizations/ author reports or articles. Since agriculture patterns of Asia and other are much different so do a comparative study, and you will find how the farming activities in all around the globe are significant contributor of GHG.

https://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-chapter8.pdf

http://unfccc.int/resource/docs/2008/smsn/igo/036.pdf

http://www.nicra.iari.res.in/Data/Climate%20Change%20Impact,%20Adaptation%20and%20Mitigation%20Print.pdf

Have an idea from here too..

https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emissions