CLIMATE MODELS : MEANING, ISSUES & WAY FORWARD

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Picture Courtesy: The Indian Express

Context:

In his address at the United Nations General Assembly US President Donald Trump claimed that climate change predictions were “wrong” and dismissed them as misleading.

What are Climate Models?

A climate model is a computer-based simulation that represents how the Earth’s climate system functions — including the atmosphere, oceans, land, and ice.
These models are built on the principles of physics, chemistry, and biology and are used to analyze how different factors — such as greenhouse gas emissions or land-use changes — influence temperature, rainfall, and weather events.

How do Climate Models work?

• Modern climate models divide the Earth into a three-dimensional grid, consisting of small “cells” that represent sections of land, air, or water. 

• Each cell uses mathematical equations to describe how energy and matter move within it and how they interact with neighboring cells. 

• Scientists input real-world data — such as CO₂ levels, ocean temperatures, and wind patterns — into these models to simulate future conditions. 

• The output provides insights into temperature and rainfall trends, sea-level rise, ice melt, and extreme weather frequency.

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Picture Courtesy: The Indian Express 

Current status of Climate Models in India:

• India has two top supercomputers for climate/weather work: Pratyush (IITM, Pune) with ~4 petaflops and Mihir (NCMRWF, Noida) with ~2.8 petaflops. (Source: The Economics Times) 

• In May 2025, the Bharat Forecast System (BFS) was launched. It’s an indigenous model with 6-km grid resolution, improving accuracy and local predictions. (Source: TOI)  

• Cyclone landfall predictions (within a 48-hour window) have improved by up to 65%. (Source: The Print) 

• Forecasts of heavy rainfall, fog, and heatwaves have improved by about 40% over the past five years. (Source: The Print) 

Evolution of Climate Models:

 Issues with Climate Models:

• Data Limitations: Many regions, especially in developing countries, lack accurate and continuous weather data. According to the World Meteorological Organization (WMO, 2024), around 60% of African weather stations and 45% of South Asian stations are either non-functional or lack regular data uploads. (Source: WMO)
• Limited Regional Accuracy: Models often divide the Earth into large grid cells (100–250 km wide). This makes them less capable of predicting local weather patterns, such as monsoon variations, urban flooding, or regional droughts. During the 2023 Himachal Pradesh floods, models underestimated rainfall intensity by 25–30%, according to the India Meteorological Department (IMD). (Source: IMD) 

• Uncertainty in Complex Processes: Natural events like volcanic eruptions, cloud formation, or El Niño are hard to simulate precisely. Models predicted the 2015–16 El Niño would cause global temperatures to rise by 0.5°C, but the actual increase was 72°C, showing sensitivity errors. (Source: IPCC Sixth Assessment Report, 2023) 

• Dependence on Assumptions: Models use assumptions about future greenhouse gas emissions, population growth, and technology use. Under Representative Concentration Pathways (RCPs) 4.5, models projected a 4°C rise by 2100, but under the high-emission RCP 8.5, the same models show a 4.3°C rise (Source: Down to Earth) 

• Calibration Bias: Most models were developed and tested in North America and Europe, where better data exists. The IMD reported that global models overestimate India’s pre-monsoon rainfall by up to 40% due to calibration issues (Source: IMD) 

Government measures to improve climate models:

• Ministry of Earth Sciences (MoES) set up: ‘Pratyush’ (Pune) and ‘Mihir’ (Noida) supercomputers, with a combined capacity of 8 petaflops, among the world’s top climate research systems. Forecast accuracy for extreme weather events improved from 60% in 2015 to 74% in 2024, according to IMD. 

• IITM Pune runs India’s Earth System Model (IITM-ESM) for studying long-term climate changes, such as monsoon variability and global warming impacts.  

• Coordinated Regional Climate Downscaling Experiment (CORDEX) – South Asia: India participates in CORDEX, an international initiative led by the World Climate Research Programme (WCRP). The project creates high-resolution regional climate models (RCMs) tailored for South Asia, improving forecasts for local weather and monsoons. 

• National Monsoon Mission (NMM): Launched in 2012 by MoES to enhance predictive capability of the Indian monsoon using advanced dynamical models. Monsoon prediction skill scores have increased from 22 (2012) to 0.45 (2024) on a scale of 0–1. 

• India collaborates with WMO, IPCC, and CMIP for sharing climate data and improving model Data from Indian satellites like INSAT-3D and SCATSAT-1 are used globally to refine climate projections. 

Way Forward:

• Expand ground-based weather stations, automatic rain gauges, and ocean buoys—especially in under-monitored regions like central India and the Himalayas. India currently has around 7,000 weather stations, but experts suggest it needs 15,000+ for finer local modeling. (Source: The Hindu) 

• Invest in next-generation supercomputers beyond Pratyush and Mihir to handle high-resolution Earth System Models. 

• Create more India-specific regional climate models (RCMs) to predict monsoon variability, floods, and droughts with greater accuracy. AI-based hybrid models have improved cyclone track prediction accuracy by up to 30%, as per MoES (2024). 

• Include human factors such as urbanization, deforestation, and energy use into models for more realistic outcomes. Real-time climate advisories are already helping over 6 million farmers under the Gramin Krishi Mausam Sewa (GKMS) (Source: PIB) 

• Strengthen partnerships between IMD, IITM, ISRO, DST, and universities for data sharing and model development. Collaborative models under CORDEX-South Asia improved monsoon simulation accuracy by 25%. 

• Train young researchers, meteorologists, and data scientists in climate modeling, big data analysis, and AI applications. 

Source: Indian Express