TOEFL統合ライティング

📖 読解文章

The introduction of electric vehicles (EVs) has been hailed as a key solution to reduce greenhouse gas emissions and dependence on fossil fuels. However, a closer examination reveals that EVs may not be as environmentally friendly as they seem. First, the production of EV batteries, particularly lithium-ion batteries, requires the mining of rare metals such as lithium, cobalt, and nickel. This mining process is highly energy-intensive and often occurs in regions with lax environmental regulations, leading to significant habitat destruction and water pollution. Second, the electricity used to charge EVs often comes from coal-fired power plants. In many countries, coal still accounts for a substantial portion of the energy mix, meaning that driving an EV indirectly emits carbon dioxide and other pollutants. Third, the disposal and recycling of EV batteries pose a serious environmental challenge. These batteries contain toxic materials that can leak into soil and groundwater if not properly managed, and current recycling rates are low due to high costs and technical difficulties. Therefore, despite their potential to reduce tailpipe emissions, EVs may ultimately have a larger environmental footprint than traditional gasoline vehicles over their entire lifecycle.

🎧 リスニング講義

The professor challenges the reading's claims about electric vehicles, arguing that the negative points are either overstated or ignore recent technological progress. First, while it is true that battery production involves mining, the professor points out that mining for lithium and cobalt is far less destructive than the extraction of oil and the refining of gasoline, which are continuous processes with massive environmental impacts. Moreover, advancements in battery technology are reducing the amount of rare metals needed, and many companies are investing in sustainable mining practices. Second, the professor acknowledges that some regions rely on coal for electricity, but she emphasizes that the global energy grid is rapidly shifting toward renewables. In many countries, the share of coal has already decreased significantly, and as more renewable energy sources are integrated, the emissions from EV charging will continue to drop. She also notes that even with a coal-heavy grid, EVs are still more efficient than internal combustion engines, resulting in lower overall emissions per mile. Third, regarding battery disposal, the professor explains that recycling technologies have improved dramatically in recent years. New methods can recover up to 95% of battery materials, and regulatory frameworks are being established to ensure responsible recycling. Additionally, second-life applications for used EV batteries, such as stationary energy storage, are becoming common, extending their usefulness before final recycling. Thus, the reading's pessimistic view fails to consider the dynamic and evolving nature of EV technology.