to the Consolidated Financial Statements under the heading “Ecuador,” beginning on page FS-39.

Environmental The following table displays the annual changes to the company’s before-tax environmental remediation reserves, including those for federal Superfund sites and analogous sites under state laws.

The company records asset retirement obligations when there is a legal obligation associated with the retirement of long-lived assets and the liability can be reasonably estimated. These asset retirement obligations include costs related to environmental issues. The liability balance of approximately $14.3 billion for asset retirement obligations at year-end 2013 related primarily to upstream properties.

For the company’s other ongoing operating assets, such as refineries and chemicals facilities, no provisions are made for exit or cleanup costs that may be required when such assets reach the end of their useful lives unless a decision to sell or otherwise abandon the facility has been made, as the indeterminate settlement dates for the asset retirements prevent estimation of the fair value of the asset retirement obligation.

Refer to the discussion below for additional information on environmental matters and their impact on Chevron, and on the company's 2013 environmental expenditures. Refer to Note 23 on pages FS-55 through FS-56 for additional discussion of environmental remediation provisions and year-end reserves. Refer also to Note 24 on page FS-56 for additional discussion of the company's asset retirement obligations.

Suspended Wells Information related to suspended wells is included in Note 19 to the Consolidated Financial Statements, Accounting for Suspended Exploratory Wells, beginning on page FS-46.

Income Taxes Information related to income tax contingencies is included on pages FS-43 through FS-45 in Note 15 and pages FS-54 through FS-55 in Note 23 to the Consolidated Financial Statements under the heading “Income Taxes.”

Other Contingencies Information related to other contingencies is included on page FS-56 in Note 23 to the Consolidated Financial Statements under the heading “Other Contingencies.”

Environmental Matters

Virtually all aspects of the businesses in which the company engages are subject to various international, federal, state and local environmental, health and safety laws, regulations and market-based programs. These regulatory requirements continue to increase in both number and complexity over time and govern not only the manner in which the company conducts its operations, but also the products it sells. Regulations intended to address concerns about greenhouse gas emissions and global climate change also continue to evolve and include those at the international or multinational (such as the mechanisms under the Kyoto Protocol and the European Union's Emissions Trading System), national (such as the U.S. Environmental Protection Agency's emission standards and renewable transportation fuel content requirements or domestic market-based programs such as those in effect in Australia and New Zealand), and state or regional (such as California's Global Warming Solutions Act) levels.

Most of the costs of